"The figures show that the United National Movement has received a majority - around 120 parliamentary seats," Zurab Kachkachishvili said.
There are 150 seats in the Georgian parliament: 75 deputies are elected according to a first-past-the-post system and 75 on the basis of proportional representation.
President Mikheil Saakashvili's United National Movement has 59.9% of the vote, while the main opposition bloc, United Opposition, is in second place with 17.65%.
The Christian Democratic Movement has 8.22% and the Labor Party 7.56%.
The Republican Party has failed to clear the 5% threshold for getting into parliament (3.75%). Other parties garnered no more than 1% of the vote.
In all, nine parties and three blocs ran in the election.
An observer mission from ex-Soviet CIS countries declared Georgia's May 21 parliamentary elections free and democratic.
The mission from 11 former Soviet republics, involving 74 observers monitoring voting at 500 polling stations in 20 constituencies, said Georgian authorities had "provided all the required conditions for monitoring."