This is a small-sized Chapel which took advantage of the surrounding agricultural area to lay its foundations. Built according to the canonical orientation, it comprises a single nave and chancel.
In the nave, the ashlars are irregular, unlike what we see in the chancel, where the ashlars are isodomic, despite having different sizes, and define rows with regular heights.
Simultaneously, the existence of decorative elements solely in the chancel, showing floral motifs, is information that confirms the existence of two different construction phases.
The main portal is slightly broken, without any decorative elements; it is merely carved into the wall's thickness, showing voussoirs with irregular profiles.
In the main façade, in addition to the portal, we find a belfry that seeks to create an illusion of verticality. It is positioned at the centre, on the gable's apex.
Closed in on itself, the Chapel of Quintã shows quite a restrained internal space, which underwent transformations over the centuries: the triumphal arch was probably transformed during the Modern Age, taking the regular nature of its voussoirs into account (when compared to the rest of the construction), although there was a reuse of a frieze from an earlier period, which is decorated with floral motifs in relief.
On the Gospel side, the solid stone pulpit with wooden baluster rails stands out, having an access staircase on its right side.
Still inside, on the apse's back wall, there is a narrow crevice of Romanesque flavour. Above the crevice, there is a round-arched niche with the image of the patron saint.