The commission had previously said that final results would be expected on Thursday.
"The Independent Electoral Commission in Iraq (IECI) will recount about 300 ballot boxes in its National Office, because the IECI discovered some discrepancies in the information," it said in a statement.
"The recounting will start at nine o'clock Iraq time on Thursday and it will be 24 hours daily until the recounting is finish. However, this procedure will delay the date of the announcement of the final results," it added.
IECI member Farid Ayar had said on Wednesday that the results would be known "in a few days".
More than 200 complaints against the 30 January election have been lodged and several votes are being verified, officials said.
Shia winning votes
According to partial results with just over half the estimated vote of about eight million counted, the main Shia coalition, the United Iraqi Alliance, leads the race, followed by a Kurdish coalition.
Iraqis elected a 275-member national assembly that will choose a president and draw up a constitution ahead of elections for a permanent government to be held in December.
Provincial councils and a parliament for the autonomous Kurdish region were also elected.