The major, in detention since 1995, was tried by the semi-traditional gacaca court of the district of Muhanga, in the south province, reported Radio Rwanda.
"After deliberation, the bench sentenced her to life imprisonment", the maximum sentence in Rwanda after the abolition of capital punishment in 2007, reports the radio.
Earlier, the medical officer "had stated that those who accused her simply wanted her head", added the radio.
She had, however, admitted not having done anything for wounded Tutsis, asserting that she was overstretched with military injuries.
Witnesses stated on Tuesday, according to Radio Rwanda, that she had ordered her close guard to kill certain Tutsis.
© Hirondelle News Agency