Chairman of the Kenyan Independent Electoral and Boundaries Commission Issack Hassan declared Deputy Prime Minister Uhuru Kenyatta beat Prime Minister Odinga in the March 4 election.
Odinga challenged the outcome of the election, saying the election results were inflated in some districts. Hassan said there wasn't much to support the prime minister's claims, however.
"The lack of credible and tangible evidence on the part of the petitioner underscores the terminal structural weakness of the petition," Hassan was quoted by The Daily Nation newspaper in Kenya as saying.
Odinga's complaints following the 2007 election led to political violence that left more than 1,000 people dead. There were few reports of violence surrounding the March 4 election, however.
Kenyatta faces the International Criminal Court in July on charges of committing crimes against humanity during the post-election violence.
International observers saw few problems other than minor vote-counting issues and long lines at the polls.