The Roman Catholic Archbishop of Toronto, currently Francis Leo, T.O.P., acts as the chancellor of the institute.

[2][3] Étienne Gilson, then of the Sorbonne, was instrumental in its foundation, along with Henry Carr and Edmund J. McCorkell of the Congregation of St.

Since 1979 the institute has hosted an annual lecture from "a senior medievalist" in honour of its co-founder and his research interests.

Previous lecturers include Jaroslav Pelikan, Mark D. Jordan, John F. Wippel, Peter Brown, and Francis Oakley.

[8] The institute has its own library with over 150,000 volumes, one of the largest collections of medieval documentation in North America.

[10] PIMS also has an extensive publishing program that includes its annual journal of research on the Middle Ages, Mediaeval Studies, which began in 1939.