The room‐temperature photoelectron kinetics in 1.3‐ and 0.4‐&mgr;m AgBr octahedral emulsion microcrystals have been investigated for time scales ranging from several nanoseconds to several microseconds after exposure. Two first‐order decay processes were observed in 1.3‐&mgr;m octahedra. The fast process is attributable to relatively shallow electron trapping that equilibrates with thermal detrapping after ∼60 nsec; the longer decay may involve ionic processes. Sulfur sensitization of the emulsion enhanced the fast electron decay rate (decay time=14 nsec). At higher levels of sulfur sensitization, the decay rate did not change with increasing sulfur levels; such behavior can indicate diffusion‐limited surface trapping. A bulk‐to‐surface electron drift mobility of 0.8 cm2/V sec on nanosecond time scales has been deduced from these kinetics. Implications of the data to current theories of photographic image formation and sulfur sensitization are discussed.