"Women's rights now," chanted the crowd, which included women dressed in abayas, or traditional long black cloaks. Some of the demonstrators wore veils over their faces.
"Our democracy will only be complete with women," said a placard written in Arabic. "We are not less, you are not more. We need a balance, open the door," said one written in English.
The crowd later attended a parliamentary session that approved a state request for a committee to speed up reviewing a bill allowing women to vote and run for parliament.
"In all Muslim countries from Indonesia to Morocco, voting and running for office are among women's rights, but we in Kuwait alone say 'No' ... Is it possible that 1 billion Muslims are wrong and we in Kuwait are right?" lawmaker Muhammad al-Saqr said to applause from female activists in the public gallery.
But the 50-man assembly, in which Islamists have a powerful bloc, did not set a date to discuss the draft law.
During the session, 10 liberal and independent lawmakers withdrew a motion to refer the election law to the Constitutional Court, Kuwait's highest court that rules on the constitutionality of laws and amendments, saying they did not want to slow the state initiative.
"We are not less, you are not more. We need a balance, open the door"
Kuwait's constitution stipulates gender equality, but parliament has blocked previous government attempts to give women suffrage.
US-allied Kuwait proposed legislation in May allowing women to vote and run in parliamentary polls after a previous attempt in 1999 was blocked by Islamist and tribal lawmakers.
Kuwaiti newspapers said Prime Minister Shaikh Sabah al-Ahmad al-Sabah had threatened to dissolve parliament if it failed to approve the latest bill.
"I am very optimistic this time around that we will get our rights because ministers and deputies are working for this," said 55-year-old Mariam al-Jassar, a retired civil servant.
"Islam does not deny women's rights," the mother of seven said.
Some lawmakers have said they will back women voting but not running. Other Islamists and tribal legislators oppose the bill.
Washington has been pressing its allies in the Middle East to bring in political reforms, saying lack of freedom and democracy have fostered violent religious militancy.
Kuwaiti women traditionally have been more liberal and educated than those in other Gulf states, who have already won political rights in Bahrain and Qatar.