The ATP Challenger Series is the second tier tour for professional tennis organised by the Association of Tennis Professionals (ATP). The 2004 calendar comprised 146 tournaments, with prize money ranging from $25,000 to $150,000.^[1][2]

Date	Country	Tournament	Prizemoney	Surface	Singles champion	Doubles champions
05.01.	Brazil	São Paulo Challenger I	$ 050,000	Hard	Juan Mónaco	Ramón Delgado André Sá
26.01.	Germany	Heilbronn Open	$ 100,000	Carpet (i)	Gilles Elseneer	Mariusz Fyrstenberg Marcin Matkowski
	United States	Hilton Waikoloa Village USTA Challenger	$ 050,000	Hard	Dmitry Tursunov	Scott Humphries Brian Vahaly

Date	Country	Tournament	Prizemoney	Surface	Singles champion	Doubles champions
02.02.	Poland	Wroclaw Challenger	$ 150,000	Hard (i)	Karol Beck	Dominik Hrbatý Michael Kohlmann
	United States	Challenger of Dallas	$ 050,000	Hard (i)	Sébastien de Chaunac	Jordan Kerr Todd Perry
	Serbia and Montenegro	Belgrade Challenger	$ 025,000	Carpet (i)	Nenad Zimonjić	Branislav Sekáč Orest Tereshchuk
	Germany	Volkswagen Challenger	$ 025,000	Carpet (i)	Michal Tabara	Robert Lindstedt Jean-Claude Scherrer
09.02.	France	Cherbourg Challenger	$ 050,000	Hard (i)	Julien Jeanpierre	Michal Mertiňák Alexander Waske
	United States	Joplin Challenger	$ 050,000	Hard (i)	Lu Yen-hsun	Lu Yen-hsun Bruno Soares
16.02.	France	Challenger 42	$ 100,000	Hard (i)	Julien Benneteau	Yves Allegro Jean-François Bachelot
23.02.	Vietnam	Heineken Challenger	$ 050,000	Hard	Arvind Parmar	Rik de Voest Fred Hemmes

Date	Country	Tournament	Prizemoney	Surface	Singles champion	Doubles champions
01.03.	France	Besançon Challenger	$ 100,000	Hard (i)	Tomáš Berdych	Alexander Waske Rogier Wassen
	Japan	Kyōto Challenger	$ 025,000	Carpet (i)	Michal Tabara	Rik de Voest Fred Hemmes
08.03.	Colombia	Bogotá Challenger	$ 025,000	Clay	Alejandro Falla	Sebastián Quintero Óscar Rodríguez
	Great Britain	Wrexham Challenger	$ 025,000	Hard (i)	Dennis van Scheppingen	Jaroslav Levinský Alexander Waske
15.03.	Mexico	Mexiko City Challenger	$ 125,000	Clay	Florian Mayer	Ashley Fisher Tripp Phillips
	United States	Boca Raton Challenger	$ 100,000	Hard	Jürgen Melzer	Igor Andreev Dmitry Tursunov
	Slovakia	Sarajevo Challenger	$ 025,000	Hard (i)	Gilles Elseneer	Jaroslav Levinský Alexander Waske
22.03.	Italy	Cagliari Challenger	$ 025,000	Clay	Didac Pérez	Tomas Behrend Giorgio Galimberti
	France	Saint-Brieuc Challenger	$ 025,000	Clay (i)	Olivier Mutis	Christophe Rochus Tom Vanhoudt
	Australia	Tasmania Challenger	$ 025,000	Hard	Lu Yen-hsun	Rik de Voest Lu Yen-hsun
29.03.	South Korea	Busan Challenger	$ 037.500	Hard	Alexander Peya	Sanchai Ratiwatana Sonchat Ratiwatana
	Italy	Barletta Challenger	$ 025,000	Clay	Nicolás Almagro	Marc López Fernando Vicente
	Australia	Canberra Challenger	$ 025,000	Clay	Peter Luczak	Łukasz Kubot Zbynek Mlynarik
	Ecuador	Salinas Challenger	$ 025,000	Hard	Alejandro Falla	Federico Browne Aisam-ul-Haq Qureshi

Date	Country	Tournament	Prizemoney	Surface	Singles champion	Doubles champions
05.04.	Mexico	San Luis Potosí Challenger	$ 050,000	Clay	Mariano Delfino	Tuomas Ketola Rogier Wassen
	United States	Calabasas Challenger	$ 025,000	Hard	Ivo Karlović	Ilija Bozoljac Dušan Vemić
12.04.	Mexico	León Challenger	$ 025,000	Hard	Jeff Morrison	Nathan Healey Tuomas Ketola
	Italy	Olbia Challenger	$ 025,000	Clay	Stefano Pescosolido	Daniele Bracciali Giorgio Galimberti
19.04.	Bermuda	Bermuda Challenger	$ 100,000	Clay	Luis Horna	Jordan Kerr Tom Vanhoudt
	Mexico	Mexiko City Challenger	$ 075,000	Hard	Florian Mayer	Ashley Fisher Tripp Phillips
	Spain	Barcelona Challenger	$ 025,000	Clay	Stan Wawrinka	Emilio Benfele Álvarez Gabriel Trujillo Soler
	Italy	Naples Challenger	$ 025,000	Clay	Gilles Müller	Tomas Behrend Giorgio Galimberti
26.04.	France	Aix-en-Provence Challenger	$ 125,000	Clay	Fabrice Santoro	Thierry Ascione Jean-François Bachelot
	Italy	Rome Challenger I	$ 025,000	Clay	Nicolas Coutelot	Kornél Bardóczky Gergely Kisgyörgy

Date	Country	Tournament	Prizemoney	Surface	Singles champion	Doubles champions
03.05.	Czech Republic	Ostrava Challenger	$ 025,000	Clay	Janko Tipsarević	Tuomas Ketola Petr Pála
10.05.	United States	Forest Hills Challenger	$ 050,000	Clay	Juan Pablo Guzmán	Jason Marshall Bruno Soares
	Croatia	Zagreb Challenger	$ 050,000	Clay	Adrián García	Karol Beck Jaroslav Levinský
	Slovakia	Košice Challenger	$ 025,000	Clay	Peter Luczak	Devin Bowen Peter Luczak
	Italy	Sanremo Challenger	$ 025,000	Clay	Potito Starace	Daniele Bracciali Giorgio Galimberti
17.05.	Czech Republic	Prague Challenger I	$ 125,000	Clay	Jan Hernych	Karol Kučera Cyril Suk
	Hungary	Budapest Challenger	$ 025,000	Clay	Stéphane Robert	Juan Pablo Brzezicki Mariano Delfino
	Uzbekistan	Fergana Challenger	$ 025,000	Hard	Igor Kunitsyn	Raven Klaasen Jean-Julien Rojer
24.05.	Slovenia	Ljubljana Challenger	$ 025,000	Clay	Jiří Vaněk	Giovanni Lapentti Rik de Voest
	Italy	Turin Challenger	$ 025,000	Clay	Álex Calatrava	Leonardo Azzaro Giorgio Galimberti
31.05.	Czech Republic	Prostějov Challenger	$ 125,000	Clay	Radek Štěpánek	Dominik Hrbatý Jaroslav Levinský
	Germany	Schickedanz Open	$ 050,000	Clay	Jiří Vaněk	Adrián García Janko Tipsarević
	Great Britain	Surbiton Challenger	$ 050,000	Grass	Karol Beck	Nathan Healey Jim Thomas
	United States	Tallahassee Challenger	$ 050,000	Hard	Cecil Mamiit	Matías Boeker Noam Okun
	Italy	Sassuolo Challenger	$ 025,000	Clay	Potito Starace	Enzo Artoni Ignacio González King

Date	Country	Tournament	Prizemoney	Surface	Singles champion	Doubles champions
07.06.	United States	Forest Hills Challenger	$ 050,000	Grass	Justin Gimelstob	Brandon Coupe Justin Gimelstob
	Switzerland	Lugano Challenger	$ 050,000	Clay	Álex Calatrava	Emilio Benfele Álvarez Giorgio Galimberti
	Germany	ATU Cup	$ 025,000	Clay	Tomáš Berdych	Janko Tipsarević Lovro Zovko
14.06.	Germany	Nord/LB Open	$ 125,000	Clay	Tomáš Berdych	Tomas Behrend Emilio Benfele Álvarez
21.06.	Andorra	Andorra Challenger	$ 025,000	Hard	Tomáš Berdych	Gilles Müller Aisam-ul-Haq Qureshi
	Italy	Reggio Emilia Challenger	$ 025,000	Clay	Olivier Mutis	Tomas Behrend Tomas Tenconi
28.06.	Spain	Córdoba Challenger	$ 100,000	Hard	Gilles Müller	Brandon Coupe Tripp Phillips
	Italy	Mantua Challenger	$ 025,000	Clay	Alessio di Mauro	Daniele Bracciali Giorgio Galimberti
	France	Montauban Challenger	$ 025,000	Clay	Álex Calatrava	Marc-Kevin Goellner Álex López Morón
	Germany	Internationale Badische Meisterschaften um den Techem Cup – Zell	$ 025,000	Clay	Daniel Elsner	Jean-Claude Scherrer Alexander Waske

Date	Country	Tournament	Prizemoney	Surface	Singles champion	Doubles champions
05.07.	Netherlands	Scheveningen Challenger	$ 050,000	Clay	Peter Wessels	Paul Logtens Raemon Sluiter
	Hungary	Budaörs Challenger	$ 025,000	Clay	Ignacio González King	Ignacio González King Gabriel Trujillo Soler
	Great Britain	Nottingham Challenger	$ 025,000	Grass	Jo-Wilfried Tsonga	Nathan Healey Tuomas Ketola
	Germany	Oberstaufen Cup	$ 025,000	Clay	Dieter Kindlmann	Vadim Davletshin Alexander Kudryavtsev
	Italy	San Benedetto Challenger	$ 025,000	Clay	Daniele Bracciali	Daniele Bracciali Giorgio Galimberti
12.07.	Canada	Granby Challenger	$ 050,000	Hard	Michael Russell	Brian Baker Frank Dancevic
	Italy	Rimini Challenger	$ 050,000	Clay	Tomas Tenconi	Daniele Bracciali Giorgio Galimberti
	Brazil	São Paulo Challenger 2	$ 050,000	Hard	André Sá	Alejandro Hernández André Sá
	Great Britain	Manchester Challenger	$ 025,000	Grass	Alex Bogdanovic	Jean-François Bachelot Nicolas Mahut
19.07.	Netherlands	Hilversum Challenger	$ 125,000	Clay	Philipp Kohlschreiber	Fred Hemmes Melle van Gemerden
	United States	Aptos Challenger	$ 050,000	Hard	Kevin Kim	Huntley Montgomery Tripp Phillips
	Brazil	Campos Challenger	$ 050,000	Hard	Takao Suzuki	Ricardo Mello Iván Miranda
	Finland	Tampere Challenger	$ 050,000	Clay	Boris Pašanski	Andres Dellatorre Diego Moyano
	Spain	Valladolid Challenger	$ 037.500	Hard	Nicolas Mahut	Jean-François Bachelot Nicolas Mahut
	Italy	Recanati Challenger	$ 025,000	Hard	Uros Vico	Massimo Dell'Acqua Uros Vico
25.07.	San Marino	San Marino Challenger	$ 100,000	Clay	Potito Starace	Massimo Bertolini Tom Vanhoudt
	Spain	Segovia Challenger	$ 100,000	Hard	Paul-Henri Mathieu	Igor Kunitsyn Vladimir Voltchkov
	United States	Lexington Challenger	$ 050,000	Hard	Matías Boeker	Matías Boeker Amer Delić
	Brazil	Belo Horizonte Challenger	$ 025,000	Hard	Janko Tipsarević	Sanchai Ratiwatana Sonchat Ratiwatana
	Russia	Togliatti Cup	$ 025,000	Hard	Jo-Wilfried Tsonga	Teymuraz Gabashvili Dmitry Vlasov

Date	Country	Tournament	Prizemoney	Surface	Singles champion	Doubles champions
02.08.	Poland	Poznań Challenger	$ 075,000	Clay	Tomáš Zíb	Adam Chadaj Stéphane Robert
	United States	Denver Challenger	$ 050,000	Hard	Brian Baker	Brian Baker Rajeev Ram
	Italy	Trani Challenger	$ 050,000	Clay	Filippo Volandri	Massimo Bertolini Álex López Morón
	Brazil	Gramado Challenger	$ 025,000	Hard	Ricardo Mello	Santiago González Bruno Soares
	Russia	Saransk Challenger	$ 025,000	Clay	Ladislav Švarc	Alexey Kedryuk Vadim Kutsenko
	Romania	Timișoara Challenger	$ 025,000	Clay	Marc Gicquel	Florin Mergea Horia Tecău
09.08.	United States	Binghamton Professional Tennis Tournament	$ 050,000	Hard	Noam Okun	Huntley Montgomery Tripp Phillips
	France	Cordenons Challenger	$ 025,000	Clay	Daniel Gimeno Traver	Leonardo Azzaro Kornél Bardóczky
	Austria	Graz Challenger	$ 025,000	Hard	Jan Minář	Julian Knowle Alexander Peya
	Ecuador	Manta Challenger	$ 025,000	Hard	Giovanni Lapentti	Marcos Daniel Santiago González
	Russia	St. Petersburg Challenger	$ 025,000	Clay	Jean-René Lisnard	Mikhail Elgin Andrei Mishin
16.08.	United States	Bronx Challenger	$ 050,000	Hard	Julien Jeanpierre	Huntley Montgomery Tripp Phillips
	Switzerland	Geneva Challenger	$ 037.500	Clay	Stan Wawrinka	Tomáš Cibulec David Škoch
	Germany	Deutsche Vermögensberatung Challenger Open	$ 025,000	Clay	Tobias Summerer	Philipp Petzschner Christopher Kas
	Uzbekistan	Samarkand Challenger	$ 025,000	Clay	Mariano Puerta	Jean-François Bachelot Melle van Gemerden
23.08.	Italy	Manerbio Challenger	$ 050,000	Clay	Nicolás Almagro	Petr Luxa Martin Štěpánek
	Uzbekistan	Bukhara Challenger	$ 025,000	Hard	Michal Mertiňák	Michal Mertiňák Pavel Šnobel
30.08.	Ukraine	Kyiv Challenger	$ 050,000	Clay	Nicolás Almagro	Albert Portas Sergio Roitman
	Germany	Black Forest Open	$ 025,000	Clay	Santiago Ventura	Gabriel Trifu Alexander Waske

Date	Country	Tournament	Prizemoney	Surface	Singles champion	Doubles champions
06.09.	Turkey	Istanbul Challenger	$ 075,000	Hard	Peter Wessels	George Bastl Björn Phau
	South Korea	Seoul Challenger	$ 075,000	Hard	Lee Hyung-taik	Ashley Fisher Robert Lindstedt
	Ukraine	Donezk Challenger	$ 050,000	Hard	Marco Chiudinelli	Igor Kunitsyn Uros Vico
	Germany	Rhein-Main Challenger	$ 025,000	Clay	Leonardo Azzaro	Ota Fukárek Jan Vacek
	Romania	Brașov Challenger	$ 025,000	Clay	Victor Ioniță	Salvador Navarro Rubén Ramírez Hidalgo
	Italy	Genova Challenger	$ 025,000	Clay	Juan Antonio Marín	Emilio Benfele Álvarez Álex López Morón
13.09.	Hungary	Budapest Challenger	$ 025,000	Clay	Stéphane Robert	Juan Pablo Brzezicki Mariano Delfino
	Iran	Tehran Challenger	$ 025,000	Clay	Mariano Puerta	Oliver Marach Jean-Claude Scherrer
20.09.	Poland	Szczecin Challenger	$ 125,000	Clay	Edgardo Massa	Lucas Arnold Ker Mariano Hood
	United States	Covington Challenger	$ 050,000	Hard	Paul Goldstein	Paul Goldstein K. J. Hippensteel
	Bosnia and Herzegovina	Banja Luka Challenger	$ 025,000	Clay	Yuri Schukin	Not completed
	China	Beijing Challenger	$ 025,000	Hard	Justin Gimelstob	Ashley Fisher Tripp Phillips
27.09.	France	Grenoble Challenger	$ 075,000	Hard (i)	Karol Kučera	Uros Vico Lovro Zovko
	United States	College Station Challenger	$ 025,000	Hard	André Sá	Paul Goldstein Brian Vahaly
	Croatia	Dubrovnik Challenger	$ 025,000	Clay	Edgardo Massa	Juan Pablo Brzezicki Martín Vassallo Argüello

Date	Country	Tournament	Prizemoney	Surface	Singles champion	Doubles champions
04.10.	United States	Austin Challenger	$ 050,000	Hard	Robert Kendrick	André Sá Bruno Soares
	Spain	Seville Challenger	$ 037.500	Clay	Óscar Hernández	Tomas Behrend Alexander Waske
	Ecuador	Quito Challenger	$ 025,000	Clay	Giovanni Lapentti	Santiago González Alejandro Hernández
	Italy	Rome Challenger II	$ 025,000	Clay	Nicolas Coutelot	Kornél Bardóczky Gergely Kisgyörgy
11.10.	United States	Tiburon Challenger	$ 050,000	Hard	K. J. Hippensteel	André Sá Bruno Soares
	Spain	Barcelona Challenger	$ 025,000	Clay	Stan Wawrinka	Emilio Benfele Álvarez Gabriel Trujillo Soler
18.10.	United States	Bolton Challenger	$ 025,000	Hard (i)	Marcos Baghdatis	Jeff Coetzee Jim Thomas
	Canada	Burbank Challenger	$ 025,000	Hard	Kevin Kim	Nick Rainey Brian Wilson

Date	Country	Tournament	Prizemoney	Surface	Singles champion	Doubles champions
01.11.	Germany	Lambertz Open by STAWAG	$ 050,000	Carpet (i)	Novak Djokovic	Simon Aspelin Todd Perry
	United States	Homestead Challenger	$ 050,000	Hard	Răzvan Sabău	Gabriel Trifu Glenn Weiner
	Chile	Santiago Challenger	$ 050,000	Clay	Óscar Hernández	Enzo Artoni Ignacio González King
	Australia	Caloundra Challenger	$ 025,000	Hard	Lu Yen-hsun	Luke Bourgeois Lu Yen-hsun
08.11.	Slovakia	Bratislava Challenger	$ 100,000	Carpet (i)	Marcos Baghdatis	Simon Aspelin Graydon Oliver
	Argentina	Buenos Aires Challenger	$ 050,000	Clay	Oliver Marach	Enzo Artoni Ignacio González King
	United States	Nashville Challenger	$ 050,000	Hard (i)	Justin Gimelstob	Jason Marshall Travis Parrott
15.11.	Ukraine	Dnipro Challenger	$ 125,000	Hard (i)	Andrei Pavel	Karol Beck Jaroslav Levinský
	France	Champaign Challenger	$ 050,000	Hard (i)	Justin Gimelstob	Brian Baker Rajeev Ram
	Finland	Helsinki Challenger	$ 050,000	Hard (i)	Peter Wessels	Robert Lindstedt Lu Yen-hsun
	Bolivia	Santa Cruz Challenger	$ 050,000	Clay	Mariano Puerta	Enzo Artoni Ignacio González King
	Germany	Okal Cup	$ 025,000	Carpet (i)	Alexander Waske	Christopher Kas Philipp Petzschner
	Mexico	Puebla Challenger	$ 025,000	Hard	Miguel Gallardo Valles	Santiago González Alejandro González
22.11.	Luxembourg	Luxemburg Challenger	$ 150,000	Hard (i)	Joachim Johansson	Massimo Bertolini Petr Luxa
	Netherlands	Groningen Challenger	$ 075,000	Hard (i)	Peter Wessels	Alexander Waske Rogier Wassen
	Colombia	Bogotá Challenger	$ 050,000	Clay	Ramón Delgado	Sergio Roitman Santiago Ventura
	Czech Republic	Prague Challenger II	$ 025,000	Carpet (i)	Tuomas Ketola	Lukáš Dlouhý Igor Zelenay
	Réunion	La Réunion Challenger	$ 025,000	Hard	Michal Tabara	Sanchai Ratiwatana Sonchat Ratiwatana
29.11.	Mauritius	Mauritius Challenger	$ 125,000	Hard	Andrei Pavel	Andrei Pavel Gabriel Trifu
	Brazil	Aracaju Challenger	$ 050,000	Clay	Nicolás Lapentti	Enzo Artoni Ignacio González King
	Italy	Milan Challenger	$ 050,000	Hard (i)	George Bastl	Daniele Bracciali Julian Knowle
	Iran	Kish Challenger	$ 025,000	Clay	Tomas Behrend	Tomas Behrend Rogier Wassen

Date	Country	Tournament	Prizemoney	Surface	Singles champion	Doubles champions
06.12.	Mexico	Guadalajara Challenger	$ 050,000	Clay	Mariano Puerta	Santiago González Alejandro González
	Austria	Ischgl Challenger	$ 050,000	Carpet (i)	Dick Norman	Leonardo Azzaro Christopher Kas