The authorities ordered some 30,000 security personnel into the streets for the vote in the wake of scattered incidents in recent months, including attacks on police posts.
But Ouattara said after casting his vote in Abidjan: "The election is taking place in a peaceful manner across the country."
The ruling coalition is seeking an absolute majority in the face of numerous dissidents and opposition candidates in the country, which was rocked by deadly unrest after the 2010 presidential election that saw Ouattara oust then leader Laurent Gbagbo.
Provisional results could start being released tonight but the definitive outcome is not expected to be known until Wednesday, according to an official from the independent election commission.
More From This Section
Former prime minister Pascal Affi Nguessan, who leads Gbagbo's Ivorian Popular Front (FPI), called for the people to "reestablish the political balance".
Ivory Coast was long the star economic performer in the region until hitting years of political strife but is now back on the rails.
The International Monetary Fund has said the west African state will be the continent's fastest-growing economy this year.
The presidential coalition -- named the Houphouetist Rally for Democracy and Peace (RHDP) in tribute to the country's founding president -- is aiming for an absolute majority in the 255-seat National Assembly.