The 15th century church of Sant' Agostino was built for Cardinal d'Estouteville by Giacomo da Pietrasanta. Sant' Agostinoin Campo Marzio, to give the church its full name, is dedicated to St Augustine of Hippo, whose mother St Monica is buried here. The inscription on the façade proclaims: GVILLERMVS DE ESTOUTEVILLA EPISC OSTIEN CARD ROTHOMAGEN S R E CAMERARIVS FECIT MCCCCLXXXIII (William d'Estouteville, Bishop of Ostia, Cardinal of Rouen of the Holy Roman Church, Camerlengo, built this in 1483).
At the west end of the church is the Madonna del Parto (1521), a much-venerated statue by Jacopo Tatti (1486-1570). The sculptor was the pupil of Andrea Sansovino (c. 1467-1529), whose name he adopted. The statue of the Madonna and Child With St Anne, by the third pillar on the left, is the work of Andrea. The fresco of the Prophet Isaiah is by Raphael.
In the first chapel on the left is the painting of the Madonna del Loreto (1604), also known as the Madonna dei Pellegrini, by Caravaggio (1571-1610).
In the chapel to the left of the choir is the tomb of St Monica.