He was a member of the Family Services Association of Metro Toronto in 1974-75, and was an advisor to the Board of Community Workers at George Brown College.
[4] After the election, the Liberals and NDP signed a two-year pact which ended forty-two years of Progressive Conservative rule.
The New Democratic Party won a majority government under Bob Rae's leadership in the 1990 provincial election, and Di Santo was appointed as chair of Ontario Workers' Compensation Board in 1991.
During his tenure as chair, he implemented progressive policies, such as the non-rebuttable presumption that workers exposed to asbestos in the workplace be compensated for their injuries/illnesses - a novelty at the time.
He campaigned for the House of Commons of Canada in the 1997 federal election, but finished third against Independent candidate John Nunziata in York South—Weston.