The legislature, dominated by presidential supporters, voted unanimously in favor.
Thousands of protesters had rallied in the city center for six days, calling for the president's resignation. Police used tear gas, water cannons and rubber bullets to disperse opposition supporters, and troops were deployed on the streets.
On Thursday Saakashvili said early presidential polls would be held on January 5 and proposed holding a simultaneous plebiscite on the date of parliamentary elections, after protesters demanded early parliamentary polls and the president's resignation.
A total of 16 people including four police officers injured in clashes on Wednesday remain in hospital, the Georgian Health Ministry said on Friday. About 600 people have sought medical treatment.