Polling booths across the Indian Ocean archipelago opened at 7:30am (0230 GMT) with the 239,000 electorate given eight and a half hours to choose between two candidates, Elections Commission official Aishath Reema told AFP.
"This time we have slightly more voters," she said adding that many had lined up to vote even before the 475 polling booths opened across the islands scattered across the equator.
After an annulled result and two cancelled polls, foreign diplomats have increasingly viewed delays as politically motivated and the European Union warned of "appropriate measures" if Saturday's election did not go ahead as scheduled.
Opposition leader Mohamed Nasheed, a former pro-democracy campaigner who won the first free polls in 2008, is the frontrunner 21 months after he resigned under pressure from demonstrations and mutinous police officers.
In a highly unusual move on the eve of a national election, the man who replaced him as president, Mohamed Waheed, left the country on Thursda