The nave of the church is dotted with thirteen burial slabs, some of which are of fine craftsmanship.

Among these is the one located at the altar of the Madonna delle Grazie; the engraving on the slab indicates that this crypt is the burial place of women devoted to the Virgin.

The slab is framed by a stone covering that features four skulls in bas-relief and other memento mori engravings.

Another burial slab, located near the entrance, is framed by an eight-pointed star.

The flooring is predominantly made up of hexagonal terracotta tiles. Bichrome ceramic tiles have been found inside the Gothic-Norman chapel and at the entrance to the chapel of the Holy Crucifix.