This Chapter Room held Assembly meetings, in which the friars discussed and made important decisions about the conventual life.
It is a large room composed of a dome from the 16th century, and modest lateral seats and furniture, which is a contrast from the rich ornamentations that make up the chapel. Authored by Tomé Velho in 1582, the room was also designed to receive the tomb of the Monastery's First Prior, who died in 1162.
The chapel was built in Renaissance style and its walls display the images of the Evangelists St. Marcos and St. Lucas on the right side and St. Mateus and St. João on the left side. The altar holds a life-size wooden sculpture of St. Teotónio, as well as his own tomb.
The sculpture presents St. Teotónio in monastic vestments, holding a staff in his right hand, the Book of the Gospels in his left hand, and a miter close to his feet, which humbly symbolises the renunciation of his episcopal dignity.
The five canvasses refer to events related to the life and miracles performed by the Holy Prior, such as the unexplainable healing of Dom Afonso Henriques and Dona Mafalda, the image of a friar watching St. Teotónio in his prime and death and finally to the centre, the representation of the Calvary.
The tomb located on the right side is from Dom João Teotónio, who was the nephew of St. Teotónio and his successor in the priory of the Monastery. On the other side is Dom Telo's tomb.