The 12-member Guardian Council winnowed the list of more than 600 would-be presidential candidates to eight men. Rafsanjani, seen as a reformer, and Esfandiar Rahim Mashaei, an ally to Iranian President Mahmoud Ahmadinejad, were among those excluded from the final list.
Rafsanjani said he entered the race to address concerns that religious principles no longer were effective governing policies. An ailing economy, a decline in Iran's international influence and rising unemployment at home were among his top platform themes.
"The main rival of all candidates is the problems facing society," he was quoted by Iran's state-funded broadcaster Press TV as saying.
Of the eight candidates, three -- chief nuclear negotiator Saeed Jalili, former policy adviser Ali Akbar Velayati, and clerical adviser Gholam Ali Haddad Adel -- are close allies of Iranian Supreme Leader Ali Khamenei.
Zahra Mostafavi Khomeini, daughter of Grand Ayatollah Ruhollah Khomeini, issued a letter to the supreme leader calling for the approval of Rafsanjani as a candidate, Radio Free Europe/Radio Liberty reports.
She said his disqualification shows "disrespect to the wishes of the people" and "great harm ... to the regime.
Presidential elections are scheduled for June 14.