The main opposition
candidate had urged his supporters to boycott the latest race, reflecting bitter divisions in the country.
In the western town of Kisumu, police threw tear gas at opposition supporters and roads remained barricaded. Voting materials arrived, but electoral commission officials could not be found at some polling stations. Many of Kisumu residents are not going to the polls in protest.
Voting appeared peaceful in most of the country. In the capital city of Nairobi, soldiers carrying long guns and tear gas canisters hovered near polling stations.
Josephine Wambui, 93, woke up at dawn to wait for her son to take her to the polling stations. She told CNN she's voted in every election since Kenya gained independence in 1963, and this will be no different.
"I am happy to vote. It is just a matter of coming to the polls and exercising my right," she said. "I have a rightful civic duty to perform."
The opposition boycott is expected to hand victory to President Uhuru Kenyatta, but in a poll that will be affected by low turnout.