To provide a projection lens which is reduced in size while preventing deterioration of optical performance.

In the projection lens, the thickest lens L34 is arranged closest to a reduction side in a first lens group G1. The projection lens satisfies the following conditional expressions simultaneously: (A): 2.0≤Bf/f≤4.5, (B): 0.15≤tg/L≤0.50, and (C): 8.0≤L/f≤17.0, where Bf is a back focus, f is the focal length of the entire lens system, tg is the thickness of the thickest lens on the optical axis, and L is the entire length of the lens. The projection lens includes, in order from an enlargement side, the first lens group G1 and a second lens group G2 having a positive refractive power, and is telecentric on the reduction side, and the projection angle toward the enlargement side exceeds 90°.