A projection lens system includes, in order from the magnification side, a negative first group G1 and positive second to fifth groups G2 to G5. In the lens system, the first group G1 has aspheric surface, a lens closest to the magnification side (L7) in the fourth group G4 has an aspheric surface, and the fifth group G5 is formed of one positive lens. During zooming, the first group G1 and the fifth group G5 remain stationary, while the second to fourth groups G2 to G4 are moved separately. Furthermore, the lens system satisfies the expression 0.8