Kostolná-Záriečie (Hungarian: Vágegyháza-Alsózáros) is a village and municipality in Trenčín District in the Trenčín Region of north-western Slovakia.

In historical records the village was first mentioned in 1318.

The municipality lies at an altitude of 206 metres and covers an area of 3.666 km². It has a population of about 645 people.

The records for genealogical research are available at the state archive "Statny Archiv in Bratislava, Slovakia"

• Roman Catholic church records (births/marriages/deaths): 1714-1896 (parish B)
• Lutheran church records (births/marriages/deaths): 1783-1895 (parish B)

• List of municipalities and towns in Slovakia

• https://web.archive.org/web/20090412234949/http://www.statistics.sk/mosmis/eng/run.html
• Surnames of living people in Kostolna Zarecie

48°52′40″N 17°58′00″E / 48.87778°N 17.96667°E / 48.87778; 17.96667