"For these crimes, and considering all relevant circumstances, the chamber sentences you Pauline Nyiramasuhuko to life imprisonment," presiding judge William Hussein Sekule said.
Nyiramasuhuko, 65 and a former minister for women's affairs, was found guilty on seven of the 11 genocide charges she faced, including conspiracy to commit genocide, genocide and "rape as a crime against humanity."
"Pauline Nyiramasuhuko conspired with other members of the interim government to commit genocide in Butare," the judge said.
"She ordered rape at the Butare prefecture office. She had superior responsibility on the Interahamwe (militia which she ordered) to commit the rapes at the Butare prefecture."
The former minister's son, Arsene Shalom Ntahobali, one of five co-accused, was also sentenced to life for crimes including genocide, extermination and rape as a crime against humanity.
Ntahobali was found guilty both of carrying out rape and of ordering other militiamen to rape.
The other co-accused, all former senior officials in the Butare area, were handed terms ranging from 25 years to life.
Former Butare prefect Sylvain Nsabimana was handed 25 years and his successor Alphonse Nteziryayo got 30 years.
Two former mayors, Joseph Kanyabashi and Elie Ndayambaje, got 35 years and life in prison respectively.
