Alassane Ouattara, the Ivorian president, has urged voters to ignore a boycott call by former president Laurent Gbagbo's party and take part in legislative elections.
"I would like to ask all my countrymen to do like me and vote for their representatives in parliament," he said after casting his ballot in Abidjan on Sunday.
"The parliament will be a truly consensual (and) democratic parliament and contribute to the strengthening of democracy in our country."
UN tanks were seen patrolling Ivory Coast's commercial capital, Abidjan, as polls opened for the first such voting since a disputed presidential poll one year ago sparked months of violence.
Violence erupted at the end of last year after the incumbent president at the time, Laurent Gbagbo, refused to step down in favour of the winner Alassane Ouattara.
Gbagbo is awaiting trial at the International Criminal Court (ICC) on charges of four counts of crimes against humanity.
He is accused of being an "indirect co-perpetrator" of murder, rape, persecution and other inhuman acts.
Earlier, Gbagbo's Ivorian Popular Front party (FPI) had called for a boycott of the elections.
The FPI said that the electoral commission is loyal to the new ruling party, and will manipulate the results, as about 950 candidates fight for 255 spots.
They also claim that the army under Ouattara's command is leading a campaign of intimidation against their supporters.
For months, a UN peacekeeping mission has been carrying out educational campaigns over the vote.
The UN has deployed 7,000 troops to provide security, and 25,000 Ivorian police and military to guard the poll.
The boycott by Gbagbo's party is seen as a politically strategic move, as for months the party has said it would only participate if the government freed the former president and his allies.
Sylvain Miaka Ouretto, who now leads the FPI called the elections a "masquerade organised by the powers in place," describing them as "not inclusive".
Gbagbo's transfer to the ICC has also given the party a justification to turn its back on the reconciliation process, which was launched formally in September.
The majority of Gbagbo's entourage are in prison or under house arrest, including his ministers and the former first lady.
Tens of thousands of his supporters are still in refugee camps in neighbouring Ghana and Liberia where they fled after Ouattara's forces seized this commercial capital.