The altar is overhung by a bas-relief in white marble on a black background that portrays "The Pietà" by an unknown master of the end of the XVI cent. that replaced a painting of the same subject ruined by the damp.
The vault is decorated with frescoes by Francesco Nappi and Girolamo Nanni, painted in the first half of the XVII cent. which represent St. Gregorio Magno and St. Bernardo di Chiaravalle's
liberation of souls from Purgatory.