The International Mission for Iraqi Elections, a 10-nation monitoring body led by Canada, recommended changes for future elections but made no call for repeating any voting from the December vote.
The results from the voting have not been announced, but are expected to show a large victory for Shiite parties. Sunni Arab leaders have denounced the voting, calling into question the results.
Some of Iraq's 220,000 election workers were among those blamed for violating their code of conduct with "questionable or illegal practices," said the report from the
Election officials received around 2,000 complaints that alleged ballot box stuffing and theft, tally sheet tampering, intimidation, violence, incorrect voter lists, ballot shortages, multiple voting, improper police and military conduct, campaigning within polling centers and violations of a pre-election ban on campaigning.
The report also said some Iraqi security forces voted on election day after voting previously on an earlier day set aside for them.
Despite the problems, the mission said Iraqis should be commended for an election that operated smoothly under harsh circumstances.
"Despite these conditions, the people of Iraq have voted in numbers that would do credit to democracies in more settled parts of the world," the report stated.
The mission gave no overall assessment on the likely integrity of the results, but said the elections' legal framework, institutions, and procedures were "designed to meet international standards."
The Independent Electoral Commission of Iraq, which oversaw the vote, investigated and resolved the most serious complaints, dismissing staff members or levying fines on those blamed for violations, the report said. Some violators were referred for criminal prosecution, it said.
The IECI also voided vote results from many polling stations where fraud was documented.
But the IECI did not have the means to investigate all complaints and did not probe "a large number." It also said additional fraud "in all probability" went undetected.