Women chanted against morality police at the Mousavi campaign event
Presidential candidate Mir-Hossein Mousavi has vowed to review laws that discriminate against women in Iran if he wins an upcoming election.
Watched by his wife, Zahra Rahnavard, Mr Mousavi told an audience of female supporters in Tehran: "We should reform laws that are unfair to women."
Patrols of so-called "morality police" regularly enforce standards of Islamic dress on Iran's streets.
Mr Mousavi, a reformist former PM, says he would seek to disband the force.
As Ms Rahnavard spoke, many in the crowd shouted protests against the morality police, who regularly arrest women they deem inappropriately dressed.
"We should prepare the ground for an Iran where women are treated without discrimination," the AFP news agency reported her as saying.
"We should reform laws that treat women unequally. We should empower women financially, women should be able to choose their professions according to their merits, and Iranian women should be able to reach the highest level of decision making bodies."
said he would put forward a bill to amend laws judged to be at odds with the spirit of Iran's constitution, in particular "discriminatory and unjust regulations" against women.
He also voiced his support for those campaigning for women's rights and pledged new legal measures to help end violence against women.
Correspondents consider Mr Mousavi the main reformist challenger to
President Mahmoud Ahmadinejad
, who is seeking another term.
He is one of four candidates approved to run in the country's president election, to be held on 12 June.
Mr Mousavi served as prime minister during the years of the Iran-Iraq war from 1980-1988.
The other candidates are a former head of Iran's powerful Revolutionary Guards, Mohsen Rezai, and Mehdi Karroubi who was a speaker of parliament and is considered a reformist.
Women's rights are an emotive issue, with both Zahra Rahnavard and the wife of his rival Mehdi Karroubi taking an active role on the campaign trail.