Aref, 61, announced on June 11 that he was withdrawing from the race, citing the urging of ally and former reformist President Mohammad Khatami aimed at united the vote behind another candidate, Hassan Rohani
Aref is a relative moderate who served as vice president under Khatami.
Aref was expected to draw support from the reformist camp, which was marginalized after the mass protests that followed Iran's 2009 election.
Aref is a university professor at Sharif University of Technology in Tehran.
During Khatami's presidency, Aref held various posts, including minister of information and communication technology.
Aref registered to run in Iran's 2008 parliamentary election but withdrew in protest against the disqualification of reformist candidates.