Self‐diffusion in pure polycrystalline silver has been measured using Ag110as a tracer. The results of the high temperature experiments, where volume diffusion is predominant, are in excellent agreement with those of other investigators. A least‐squares calculation using all available data on volume diffusion of silver gives as a value for the diffusion coefficientD=0.724e−45, 500/RT. The occurence at low temperatures of grain boundary diffusion, in which the activity decreases exponentially with the first power of the penetration depth, as reported by Hoffman and Turnbull, is confirmed.