Egyptians have approved constitutional changes that open the way for multi-candidate presidential elections.
Voting on Wednesday was marred by violence
According to official results 83% voted "Yes" to the changes, with 54% of registered voters going to the polls.
Six opposition parties, including the Muslim Brotherhood, called for a boycott of the referendum.
They say the amendments contain too many constraints for anyone to challenge President Hosni Mubarak and his ruling National Democratic Party.
Voting on Wednesday was marred by clashes, including the beating of opposition protesters by government agents and supporters.
Official and pro-government newspapers hailed Wednesday's referendum as a defeat for the boycott.
Elections in Egypt generally suffer voter apathy bred by decades of authoritarian rule and ballot rigging, analysts say.
President Mubarak, who has ruled Egypt for almost 25 years, is widely expected to seek another term in office in elections due later this year.