In the period between 1972 and 1974, Petrić was a visiting professor at the Department of English Language and Literature at the State University of New York (SUNY). Petrić was then offered the Henry Luce Chair of Cinema at Harvard University in 1972 and remained in that position until 1997. During this period, he also lectured extensively at universities across the United States and Europe. Together with the legendary documentarian Robert Gardner and the influential philosopher Stanley Cavell he established the Harvard Film Archive and served as its Founding Curator until his retirement in 1997.
