Kloster der Barmherzigen Brüder, Prag, Hospital monastery in Old Town, Prague, Czech Republic

The Monastery of the Brothers of Mercy Na Františku, with the Church of Saints Simon and Jude, occupies the site of a 14th-century hospital on the Old Town bank of the Vltava. The church built after 1620 is a single-nave Gothic-Renaissance structure; only the north aisle of the earlier Bohemian Brethren church was kept, separated from the new nave by a wall. The convent and hospital wings took shape between 1620 and 1653 and were largely rebuilt in Baroque style around 1700–1730.

The Church of Saints Simon and Jude was first recorded in 1354 and kept its original floor plan without vaulting. The Brothers of Mercy took over the complex later and transformed it into an important medical center for Prague.

The site's name, Na Františku, comes from the Franciscan monastery that once stood nearby. The Brothers of Mercy, a hospital order, took over the complex on Christmas Eve 1620 from King Ferdinand II and ran a hospital here; the adjacent Nemocnice Na Františku continues that medical use. The church is dedicated to Saints Simon and Jude, and the former convent buildings now serve as an official residence.

The monastery stands in the Na Františku locality of Prague's Old Town, on the bank of the Vltava, with the church of Saints Simon and Jude facing Dušní Street. The complex took shape between 1620 and 1653 on the site of a vanished hospital, and the hospital wings were rebuilt again in the 20th century. The buildings are still used by the hospital Na Františku, so parts of the grounds are not open to casual wandering.

The monastery church was built on the site of a Bohemian Brethren congregation hall whose vault collapsed during construction in 1617, delaying consecration until 14 June 1620. The Brothers of Mercy received the whole complex from King Ferdinand II on Christmas Eve 1620 and began building anew almost at once.