Inside may be seen frescoes of St. Anthony Abbot and St. Paul of Thebes by Giovanni Lanfranco; these were removed and transferred to this church from a now-lost structure built by Odoardo Farnese. [...]
Additionally, the church houses a chamber decorated with human bones; a large number of skulls, candelabras constructed of bones, and a large cross adorned with skulls are among the room's adornments. This chamber is located through a door to the left of the main altar and is rarely open to visitors.
Santa Maria was built by a confraternity that assumed responsibility for interring abandoned corpses in Rome. It is remarkable for the depictions of laureled skulls over the façade entrance and other death imagery. In this it has some of the morbid encrustations also seen in the Roman church of the Capuchins. Its charity was, and still is, supported by the Arciconfraternita di Santa Maria dell'Orazione e Morte, a purgatorial society dating to the 1560s. Burials were performed in their cemetery, once sited on the banks of the Tiber adjacent to the church. Architect Fuga and San Carlo Borromeo were members of the fraternity.