A case is presented in which a patient with prominent depression and a background of longstanding but controlled epilepsy underwent EST. Inadvertent interruption of the anticonvulsant medication in the course of hospitalization was followed by postictal phenomena characterized by catatonic-like stupor and coma associated with an abnormal but not sufficiently diagnostic EEG. The stupor cleared gradually upon administration of Mesantoin and barbiturate. This case emphasizes the importance of careful history and the maintenance of appropriate anticonvulsant medication in epileptic patients undergoing shock therapy. Post- or inter-ictal stupor once precipitated presents a state difficult to diagnose with certainty and a challenging management problem.