Sierra Leone will hold a runoff vote after neither main opposition leader Julius Maada Bio nor ruling party candidate Samura Kamara cleared a 55 percent threshold.
Sierra Leone will hold a presidential runoff vote on March 27, the electoral commission said on Tuesday.
Julius Maada Bio, leader of the opposition People's Party, picked up 43.3 percent of votes in the March 7 election, while Samura Kamara of the All Peoples Congress (APC) won 42.7 percent, the commission said.
President Ernest Bai Koroma is stepping down after serving a maximum of two five-year terms in office. He had tapped former foreign minister Kamara, 76, to run for APC against 53-year-old Bio, a former junta leader.
The two parties have dominated politics in Sierra Leone since the West African country became independent from Britain in 1961.
A total of 16 candidates ran in the presidential polls on March 7. European Union observers described the vote as generally "transparent, credible and well-organized," but noted there had been concerns about "intimidation and violence" in some areas.
Whoever is ultimately declared president faces a number of significant challenges. The economy of the poverty-stricken country is in a poor state following a commodity price slump and an ebola epidemic that killed thousands of people.