Intracellular recordings were made from Renshaw cells in the cat. Recurrent excitatory postsynaptic potentials (EPSPs) were elicited by antidromic stimulation of the ventral roots. These EPSPs had a simple monophasic time course without a spike-like peak reported by previous authors. No hyperpolarization could be detected following averaged EPSPs. However, after bursts of impulses an afterhyperpolarization could be detected which probably contributes to a pause in firing after the initial response. Depolarizing current pulses elicited a burst of impulses similar in pattern to the initial response to stimulation of the ventral roots.