Opposition leaders handed a protest letter to Levan Tarkhnishvili at the CEC office on Tuesday.
They said complete information about election law violations would be presented later today at a special briefing.
United opposition candidate Levan Gachechiladze has demanded airtime to "tell the truth about the way the election was falsified."
National media said on Monday election authorities had received about 450 complaints over alleged violations.
U.S. State Department spokesman Sean McCormack said monitors had "identified significant problems that must be corrected."
"We encourage all political forces to work peacefully and responsibly for a democratic Georgia," McCormack said.
With 87% of the votes counted, Saakashvili is in the lead with 52.1% of the vote, his nearest challenger Gachechiladze trailing with 24.98%, followed by businessman Badri Patarkatsishvili with 6.66%, Labor Party leader Shalva Natelashvili with 6.33%, New Rights party leader David Gamkrelidze with 3.91%, and others gaining less than 1%.