All eyes are on Nigeria's Independent National Electoral Commission (INEC).
In this polling station in Lagos, Saturday (Feb. 25), voters were optimistic the election would be transparent.
"The general election is going to be a free and fair one considering what I've seen, I just came out to do the accreditation and people are coming out to do the same thing also," Oluchi Obinyera said.
Peter Okechukwu also commended the process so far: "The effort INEC have been putting in place, the way they are doing things, the sensation they have been giving to people, I think the election is going to be free and fair."
To ensure the presidential and parliamentary elections are fair, INEC introduced biometric voter IDs among other things.
176.000 polling stations were set to welcome Nigerians from 7:30 pm (GMT) to 1:30 pm (GMT), Saturday.
Local media reported incidents including late arrivals of the commission's staff.
Results in Kano, the second largest northern city are highly anticipated as some experts believe they will be decisive.
Voter Nnamdi Aguhara said he expected more efforts from INEC: "I walked a long distance to get to this place and I would say, getting to my polling unit, I can see the turnout is actually great but on the part of the INEC officials turning up, well, we expected more from them actually, at least for them to be here."