Tamari has been a sociologist at Birzeit University since 1971. In 1994, he was appointed director of the Institute of Jerusalem Studies, an affiliate of the Beirut-based Institute for Palestine Studies that publishes the Arabic journal Jerusalem Quarterly (formerly Jerusalem Quarterly File). He has also served on the refugee committee in the multilateral peace talks held following the Madrid Conference of 1991. He has been a visiting fellow at the Aga Khan Program for Islamic Architecture at MIT, and has been a visiting professor at the University of California Berkeley (2005, 2007), New York University (2001–03); Cornell University (1997), and the University of Chicago (1991–92). He was a 2008 Eric Lane Fellow at the University of Cambridge and is a lecturer in Mediterranean Studies at the Ca' Foscari University of Venice.