Designed in the second half of the 16th century by Ottavio Nonni (1524-1606), known as the Mascherino, as the residence of Cardinal Prospero Santacroce, the Palazzo was purchased in 1591 by the Petrignani family, who later sold it to the Monte di Pietà, a charitable relief organization.

The expansion works for the new purpose were carried out by Maderno (1556-1629). The internal chapel, a jewel of Baroque architecture, rich in marble and sculptures, is also by him.

The wide main façade of the Palazzo, with two portals separated by a fountain, has as its only decoration in the middle an aedicule and the heraldic coats of arms of Paul III Farnese, Clement VIII Aldobrandini and his nephew, Cardinal Pietro Aldobrandini. On the left there is a large clock surmounted by a sail-shaped bell tower.

Even today its function as a Monte dei Pegni remains active.