There are two fundamental elements to the role of the University Health Network's Board of Trustees: decision-making and oversight. The decision-making function is exercised with respect to the formulation (with management) of strategic policies, strategic goals and approval of significant actions; the oversight function concerns the review of management decisions, the adequacy of systems and controls and the implementation of strategic policies.

The board establishes formal delegations of authority, defining the limits of management’s power and responsibility and delegating to management certain powers to manage the operation of the hospital. There are also statutory limitations specifying responsibilities of the board that cannot be delegated. Responsibilities not delegated to management remain with the board.

The Board of Trustees at the University Health Network is responsible for maintaining accountability and providing stewardship. The Board of Trustees consists of both appointed and elected trustees. Each trustee’s position is for a term of three years. Appointed trustees initially included two from Cancer Care Ontario and four from the University of Toronto.

There are three advisory committees to UHN's Board of Trustees: Finance and Audit Committee, Quality Committee and Governance/Nominating Committee.

The position of Chair of the Board of Trustees has been held by Fredrik S. Eaton (1999-2000), Anthony S. Fell (2000-2005), and Philip Orsino (2005-2009), John Mulvihill (2009- ).