The last stage in a tour of the Museum, the Sacristy houses two nineteenth-century funerary monuments still dedicated to members of the di Sangro family. Various marbles dating back to the seventeenth-century decoration of the Sansevero Chapel may be seen on the wall, together with large slabs of the eighteenth-century labyrinth flooring.

Since 2005 the Sacristy has been home to the Madonna with Child, by Giuseppe Pesce, a painting in coloured wax devised by Raimondo di Sangro. As of 2020, it is also possible to admire the Portrait of Raimondo di Sangro by Francesco De Mura, the Sansevero Chapel Museum’s latest acquisition.

The Sacristy currently also houses the Museum’s bookshop, renovated in 2017 with functional furnishings. The design is inspired by the motif of the labyrinthine floor of the Sansevero Chapel and is the work of Francesco Celebrano. It was commissioned by Raimondo di Sangro in the second half of the eighteenth century.