The Chapter House is the prettiest room in the Tibães Monastery. It's where they made many big decisions, such as choosing the rulers of each monastery every three years. It was built in 1700, but later it was completely reconstructed in 1783. It is a very large, rectangular room with a coffered ceiling covered with carved and painted wood, with a wooden border around the perimeter that is carved with floral motifs, and birds and angels' heads.
It has three large windows and an altar dedicated to Frei José de Santo António Vilaça and an allusive picture of the Holy Spirit. The walls are covered with tile panels with a Rococo style that depicts scenes from Joseph's life in Egypt.