Leon Mugesera, an academic, was extradited back to his home country from Canada four years ago.
He made his incendiary speech against the Tutsi minority in 1992. Some 800,000 people died in the genocide.
Mugesera later worked as a lecturer in Quebec province and lost a 12-year legal battle to avoid extradition.
In 1992, then an official in Rwanda's ruling Hutu party, Mugesera  told more than 1,000 party members that they should kill Tutsis and dump their bodies in the river.
Mugesera later maintained his innocence, saying the speech had been taken out of context.
The genocide ended when rebels, led by current Tutsi President Paul Kagame, seized power in July 1994.
Militias from the majority Hutu ethnic group were blamed for the mass slaughter.
A former politician who described Tutsis as "cockroaches" and called for their extermination has been jailed for life in Rwanda over the 1994 genocide.