Transient gain has been observed on theC→Atransition of XeF*. Measurements made at 488.0 and 475.9 nm showed a peak gain of 8&percent; through a short cell filled with Ar/Xe/NF3mixtures and excited by a short electron‐beam pulse. A stimulated emission cross section of 5×10−18cm2is derived, consistent with the measured linewidth and radiative lifetime of theC‐Atransition. Weaker amplification was observed at 514.5 nm.