Niger could see its first democratic transition of power since independence in the elections being held on Sunday amid a growing threat from jihadists in the region.
President Mahamadou Issoufou, who has served two terms, is stepping down, paving the way for the first peaceful transfer of power between two elected presidents since independence from France in 1960. Niger has seen four coups.
The transfer would be significant not only in Niger but also in West Africa, where leaders recently have held on for disputed third terms in Guinea and Ivory Coast.
More than 7.4 million Nigeriens are registered to vote, and 30 candidates are running for president while 171 seats are being contested in the national assembly.
The next president will have to deal with major problems including extremism, poverty, displacement and corruption. Attacks by extremists affected local elections two weeks ago as Nigeria-based Boko Haram fighters killed more than 28 people in Toumour in the Diffa region the day before the vote.
Niger also faces increasing attacks from fighters linked to the Islamic State group and al-Qaida. Thousands of people have been killed and hundreds of thousands have been displaced despite the presence of thousands of regional and international troops.