European monitors said that the election did not live up to the country's democratic potential but had expressed the will of the people.
The United National Movement picked up more than 100 seats in the 150-member legislature, while the nine-party opposition bloc won just 30 seats.
Opposition politicians cut up the certificates granting them seats in the legislature rather than enter the session.
But the crowds were far smaller than the tens of thousands of people that gathered after the results were announced in May.
The new parliament had originally been expected to sit for the first time on Tuesday.
|"A group of bandits has seized power"|
Koba Davitashvili, opposition leader
David Gamkrelidze, the co-leader of United Opposition, said that the change of date and the presence of riot police outside the building "shows that this is not a popularly elected parliament".
Koba Davitashvili, another opposition leader, said "a group of bandits has seized power".
Inside parliament, Saakashvili addressed the session saying that parliament's main task was to restore Georgian unity.
"Our parliament must root our poverty, give people jobs and battle all those problems which we have inherited," he said.
"Our principal value is the unity of Georgia. Your parliament must resolve historical tasks."
While they support Saakashvili's pro-Western course and Nato membership goals, they have accused him of posturing on the international stage and neglecting the poor.