With 45% of the vote counted, President Mikheil Saakashvili's United National Movement has 61.79% of the vote, while the main opposition bloc, United Opposition, is in second place with 14.82%.
However, the opposition said soon after the polls closed that it had won the election, and threatened to start a "people's rebellion" if the results were rigged.
The head of the CIS mission, Nauryz Aidarov, told journalists in Tbilisi on Thursday: "The elections were calm and democratic, and the fact that there were some violations cannot influence the outcome of the vote."
The mission from 11 former Soviet republics, involving 74 people monitoring voting in 500 ballot stations in 20 constituencies, said Georgian authorities had "provided all necessary conditions for monitoring."
However, Russian political analyst Alexander Karavayev said the election could not be called 'fair' as the opposition did not have enough access to media resources during the election campaign.
Saakashvili "simply created conditions that prevented the opposition from gathering rallies with thousands of participants, so that he did not have to use force in the streets," Karavayev said.
Konstantin Zatulin, director of the Institute of CIS Studies, has warned that the results of the election to the 150-member parliament could lead to another political crisis.
However, he said the opposition was not likely to seize power if it staged street protests, but that more public unrest would 'annul Saakashvili's results and create conditions for forming a more powerful opposition."
Tbilisi saw six days of mass opposition rallies last November with protesters demanding Saakashvili's resignation over allegations of corruption and increasing authoritarianism.
The Georgian leader was forced to step down after the protests in the capital turned violent and police brutally dispersed protesters demanding his resignation as president, a post he had occupied since early 2004, following the 2003 bloodless 'Rose' revolution that saw Eduard Shevardnadze removed from power.
Saakashvili subsequently called early elections for January and was reelected with 53% of the vote.
