The Sacristy of São Roque is important, both symbolically and artistically, for being one of the earliest sacristies constructed by the Sociaty of Jesus, conceived in line with the liturgical recommendations emanating from the Council of Trent. Church sacristies took on the added function os "art galleries" for the edification of the faithful. The Jesuits of São Roque werw in the forefront of this devellopment.
In the sacristy are two large valuable 17 century chests of drawers made of jacaranda and of rose wood overlaidwith ebony and inlaid with ivory. The walls are almost completely covered with threerows of valuable paintings laid out in superimposed friezes up the vaulted ceiling.
The ceiling of the sacrity composed of a round vault divided into coffers decorated with 17 century frescos wich contain emblems with Biblical symbols alluding to the Virgin Mary, later integrated into a "Litany os the Virgin".