Following the Iranian Revolution Haddad-Adel became a member of the Islamic Republic Party and he served in many governmental posts, including deputy culture and Islamic guidance minister (1979) and deputy education minister (1982–1993). Since 1995 he has been serving as the head of the Iranian Academy of Persian Language and Literature (except for August 2004 – 2008).He is also the executive director of the Islamic Encyclopedia Foundation. He contributed to the establishment of the national Scientific Olympiads in Homeland.Haddad-Adel served at the Majlis for thirteen years, over four terms. He officially ranked as the 33rd candidate of Tehran in the 2000 parliamentary election after recounts by the Council of Guardians which led to an annulment of 700,000 Tehrani votes and the removal of Alireza Rajaei and Ali Akbar Rahmani from the top 30, and the withdrawal of Akbar Hashemi Rafsanjani. Haddad-Adel collected the most votes from Tehran four years later, while most Tehranis refused to vote in 2004 election because many reformist candidates where not allowed to run.