Iran's conservative president, Mahmoud Ahmadinejad, was quoted on Monday on state television as saying the presence of women and families in stadiums would "promote chastity".
"The best stands should be allocated to women and families in the stadiums in which national and important matches are being held," Ahmadinejad was quoted as saying
"The presence of women and families in public places promotes chastity."
Unruly male fans
Since the Islamic Republic was installed after a 1979 revolution, most Iranian women have been barred from attending matches, such as national football games, in big stadiums.
"The presence of women and families in public places promotes chastity"
Initially, authorities justified the ban by saying women should not watch men wearing shorts, but more recently officials have said it is inappropriate for women to be in crowds where strong language or bad behaviour is expected.
Only a tiny number of women have been allowed inside stadiums. They were restricted to VIP sections and could only enter if they had official invitation cards.
Female journalists were given highly restricted access to major sporting events.
Dressing as men
By contrast, female fans of visiting foreign teams were allowed at sports' events unhindered, drawing the ire of local women.
In the past, women had occasionally scuffled with police when they were barred from entering stadiums. Some tried to go inside dressed as men or sneaked in with the foreign fans.
"I'm happy that for the first time we will be allowed to enter the stadiums like ordinary human beings,"
Women had sometimes been allowed into smaller sports venues to watch male sports, such as basketball or volleyball.
Ban lift hailed
Prominent Iranian women's rights activists immediately welcomed the announcement.
"I'm happy that for the first time we will be allowed to enter the stadiums like ordinary human beings," said Parastoo Dokouhaki, a writer who has campaigned for female stadium access for years.
"Before they used to sell us tickets but would then not allow us in. There was no law behind the ban, but with this order we will finally be allowed in. I'm happy about this."
"Our efforts have finally born fruit," said Mahbubeh Abbasgholizadeh, another feminist activist who was once injured by police while staging a protest outside Tehran's Azadi stadium.
"This decision is a positive and logical response."
A state television announcer reported that Ahmadinejad "ordered the head of the sports organisation to provide facilities in the stadiums to watch national matches."
Some analysts have said the softer line might be because the government does not want to alienate any part of the population when it is under mounting international pressure over its nuclear programme.
Enforcement of strict moral codes governing women's dress, Western music and mingling of the sexes became more lax after Mohammad Khatami became president in 1997 on a platform of reforms. But even under him, women were barred from stadiums.
"This decision is a positive and logical response"
Mahbubeh Abbasgholizadeh, an Iranian feminist
Since Ahmadinejad won the presidency last year with the backing of conservative clerics and Basij religious militias, hardliners have pressed for tighter controls on "immoral behaviour". Many expected tougher rules would follow.
Ahmadinejad was elected after promising a return to the values of the spiritual and political leader behind the 1979 revolution, Ayatollah Khomeini.