The church stands next to the old hospital, where the medieval monastery dedicated precisely to St. John the Baptist used to be, first used by the Augustinian nuns of St. Jerome, then by the Girolamini fathers of the congregation of Blessed Peter of Pisa (1492-1810). The monastery was later sold as national property and purchased by Ludovico Piermarini and to be later converted into an active civil hospital until 2006.
The church building dates back to the 13th century and was renovated several times, especially with the addition of altars, which from six became eight in 1719-20.
In 1810, due to suppressions, the building became private property and Ludovico Piermarini opened a wax factory there. Fortunately, it is recovered today.
The interior has a single nave with barrel vaults. To this day the fresco decorations that adorned the walls are much compromised. Of note are the 15th-15th century frescoes with "Madonna Enthroned with Child, Angels, St. Anthony of Padua and Holy Bishop" and "Crucifixion" by Bernardino and Pierantonio Mezzastris. Coeval the "Nativity" painted by Feliciano de' Nuti.
In the apse basin a "Coronation of the Virgin" is attributed to the Nasini (Tommaso?) circle.
Behind the 18th-century altar a 17th-century wooden crucifix.