The effect of various rare‐gas diluents on the operating parameters of the XeCl laser has been investigated. The laser was electron‐beam pumped at an excitation rate of ≊3 MW/cm3and a pulse duration of 50 nsec. Contrary to previous results we found that the intrinsic efficiency, small‐signal gain, and absorption were independent of the rare‐gas diluent. The intrinsic efficiency was ≊ 4%, the small‐signal gain was 0.18 cm−1, and the absorption coefficient was between 0.04 and 0.05 cm−1. A saturation intensity of 3 MW/cm2was obtained from a modified Rigrod analysis of the data.