Kostel Panny Marie Matky Ustavičné Pomoci, also known as U Kajetánů, is a Roman Catholic monastic church located on Nerudově ulice in Malá Strana, Prague 1. Constructed between the late 17th and early 18th centuries, it features an innovative Baroque style with an oval nave and dynamic facade. Consecrated in 1717, it has been a significant religious site since then and was recognized as a national cultural monument in 1964.

The church's origins date back to the late 17th century when Guarino Guarini, a renowned architect and mathematician of the Theatine order, designed it. Initially planned for another location, logistical challenges, including the demolition of Strahovská brána, led to its construction on Malá Strana. Construction began in 1691 with a foundation stone laid by Archbishop Jan Bedřich z Valdštejna and concluded around the early 18th century. The consecration took place on September 29, 1717, officiated by Daniel Josef Mayer z Mayernu.

Architecturally, Kostel Panny Marie Matky Ustavičné Pomoci showcases Guarini’s forward-thinking design, which predated similar developments in Prague. It features an oval nave intersected with semi-circular chapels and a central dome, creating a unique interior layout that reflects the radical Baroque style. Giovanni Domenico Orsi likely oversaw its construction, contributing to its distinctive facade. Later 19th-century modifications by the Redemptorists further enhanced its architectural significance.

Throughout history, the church has had various owners and administrators. Initially managed by the Theatine order from 1691 until their dissolution during the Josephinian reforms in 1789, it was then overseen by the Religious Matice. In 1869, Emperor Ferdinand I. Dobrotivý and his wife Maria Anna Savojská acquired the church for the Redemptorists, who have managed it since, except from 1950 to 2004 when it was under the Prague archdiocese's administration.

Key events include its foundation stone laying in 1691 and consecration in 1717. The transition to Redemptorist management in 1869 marked a significant change, with further renovations enhancing its religious and architectural stature. From 2018 to 2021, it was managed by the Vojenského a špitálního řádu sv. Lazara Jeruzalémského – Bohemia, restoring historical elements and maintaining traditional Roman Catholic rituals.

Today, Kostel Panny Marie Matky Ustavičné Pomoci remains open to visitors for prayer and reflection, offering insight into its rich history and architectural beauty. Its status as a national cultural monument underscores its importance in Prague's religious and cultural landscape. Visitors are invited to explore this remarkable site, appreciating its historical significance and the serene atmosphere it provides amidst Malá Strana's historic surroundings.