30 July 2013 Last updated at 21:31 ET 
Thousands have attended rallies in the run up to the vote
Zimbabweans are heading to the polls to elect a president, with a high turnout expected.
On Tuesday, incumbent Robert Mugabe said he would resign after 33 years in power if he loses.
His remarks came as Prime Minister Morgan Tsvangirai's Movement for Democratic Change (MDC) party accused Zanu-PF of doctoring the electoral roll. Zanu-PF denied the accusation.
Campaigning has been peaceful, with no reports of violence or intimidation.
The last presidential poll five years ago were overshadowed by myriad problems, including violence.
Voting begins at 07:00 (05:00 GMT) and close at 19:00 (17:00 GMT), with results expected within five days.
The situation has been relatively calm ahead of the poll, with most bars in the capital Harare full on Tuesday night, given that Wednesday was declared a holiday to allow for voting, the BBC's Brian Hungwe reports from Harare.
Please turn on JavaScript. Media requires JavaScript to play.
The BBC's Nomsa Maseko was the journalist who asked Mr Mugabe if he would step down if he lost
Amongst the topics discussed by Harareans on the eve of the poll was the conduct of parties before the elections, and the political implications of victory or defeat for Mr Mugabe, our correspondent adds.
A large turn out is expected, given the tens of thousands of people who have gone to rallies staged by the candidates in recent weeks.
Jovial mood Zanu-PF responded to the allegations surrounding the electoral roll by saying it was the responsibility of the Zimbabwe Electoral Commission (Zec), which released the roll only on the eve of polls.
A Zanu-PF spokesman pointed out that appointees from both parties are on the commission and accused the MDC Finance Minister Tendai Biti of not funding Zec properly.
Zec has not commented on the allegations.
Continue reading the main story Zimbabwe election: Key facts
- About 6.4 million registered voters
- Polls open at 05:00 GMT and close at 17:00 GMT
- Vote for president and parliament
- Zanu-PF's Robert Mugabe and MDC's Morgan Tsvangirai are the main contenders
- Mr Mugabe, 89, is seeking to extend his 33-year rule
- Mr Tsvangirai, 61, hopes to become president after three failed attempts
- The poll ends the fractious coalition between Zanu-PF and MDC, which was brokered by regional mediators after disputed elections in 2008 that were marred by violence
A BBC correspondent who saw the electoral roll seen the document and says it features the names of thousands of dead people.
Some names also appear twice or three times with variations to their ID numbers or home address.
The two long-time rivals have been sharing power since 2009, under a deal brokered by the regional bloc to end conflict that marred elections in 2008.
At a press conference at State House in the capital, Harare, Mr Mugabe told journalists that he and Mr Tsvangirai had learnt to work together and could even share a pot of tea.
Responding to a question from the BBC, the president, who was in a jovial mood, said he would step down if he lost and insisted that there had been "no cheating".
But the MDC has said the electoral roll released on Tuesday by Zec dates back to 1985 and is full of anomalies.
Please turn on JavaScript. Media requires JavaScript to play.
Mark Lowen meets Zimbabweans living in South Africa preparing to return home to vote
Three other candidates are also standing for president and voters will also be electing news members of parliament.
Bulawayo-based journalist Thabo Kunene told the BBC that many Zimbabweans have been returning home from South Africa to vote.
Taxis and buses carrying the exiles continued to arrive in the southern city on Tuesday afternoon, he said.
In Bulawayo's oldest township of Makhokhoba, MDC and Zanu-PF campaign teams met amicably at one house during their door-to-door campaign - waving each other's flags - a sign that some Zimbabweans have matured and no longer believed in violence, he added.
In 2008, Mr Tsvangirai pulled out of run-off vote, accusing pro-Mugabe militias and the security forces of attacking his supporters after he gained most votes in the first round.
