Mamadou Tandja said the MPs elected would be "patriots"
Voters in Niger are electing new MPs after President Mamadou Tandja sacked parliament last year for rejecting his attempts to extend his stay in power.
The opposition has boycotted the vote, being held despite international calls for it be postponed.
The constitution was changed after Mr Tandja held a referendum, also boycotted by the opposition.
A BBC reporter in Niger says turnout has been steady, with some candidates laying on minibuses for voters.
Mr Tandja, 71, voted early in the capital Niamey.
"I hope this day will be good for Niger, that the voting passes off smoothly and that the MPs elected will be patriots," he said, surrounded by heavy security, according to the AFP news agency.
The BBC's Idy Baraou, in Niamey, says there has been a huge deployment of military and paramilitary forces to ensure the vote passes off without incident.
He says groups of opposition supporters have gathered outside their party offices, but any active protest is unlikely.
The government has pressed on with the election despite criticism from the African Union and the European Union.
Mr Tandja was due to stand down in December, after serving two five-year terms.
Critics say the poll is a farce designed to help perpetuate Mr Tandja's rule
Opposition groups say Mr Tandja wants to hold on to power for life, and has scheduled the election to give his rule a veneer of legitimacy.
His supporters insist that he has helped improve living standards in one of the world's poorest countries and so should be allowed to continue with his work.
Niger is one of the world's major sources of uranium.
In January, French company Areva signed a deal to develop what it said would become the world's second biggest uranium mine.
The mine is in the semi-desert north, where ethnic Tuareg rebels have fighting for more autonomy.
President Tandja has signed a peace deal with several Tuareg groups.
He was first elected president in 1999 and won re-election in 2004.
Six million people are eligible to vote to elect a new 113-member parliament, but correspondents say the campaign has been marked by indifference among residents.