Jailed candidate among top contenders to challenge President Issoufou, as voters also choose new parliament.
Niger’s president has been re-elected as his main opponent remains in France seeking medical treatment after being jailed for several months.
The electoral commission released results on Tuesday showing that President Mahamadou Issoufou received more than 92 percent of the runoff vote.
His rival Hama Amadou received 18 percent of the vote, which saw a low turnout after the opposition called for a boycott.
Amadou was arrested and held from November until March for alleged involvement in a baby-trafficking scheme, a charge he has dismissed as politically motivated.
He still was given the all-clear to run in the election for the Nigerian Democratic Movement party but only days before the vote, he was flown to Paris on medical grounds.
Despite large uranium deposits and other resources, Niger is one of the world’s poorest countries.
Apart from political turmoil, the landlocked country is under constant threat from al-Qaeda-linked fighters to the north and west, and Boko Haram in the south.