Zimbabwean President Emmerson Mnangagwa cast his ballot Monday morning in the first post-Mugabe election in Kwekwe in his home province of Midlands.
His main rival Nelson Chamisa of the opposition MDC Alliance also cast his vote in the capital Harare.
Mnangagwa told reporters soon after casting his vote that Zimbabwe was enjoying an unprecedented democratic space.
He also said former president Robert Mugabe was entitled to express his views.
Mugabe, ousted in November last year following a military intervention, said Sunday he will vote for the opposition, dumping the ruling ZANU-PF party which he founded in 1963.
"I can assure you that this country is enjoying democratic space which has never been experienced before. The former president has his right to express his views," Mnangagwa said.
Zimbabweans are voting to choose a president, National Assembly members and councilors.
There are 5.6 million people registered to vote in the polls.
Voting is scheduled to end at 7 pm.