Cognitive deficits are commonly associated with maintenance electroconvulsive therapy (ECT). Treatment of these cognitive deficits is important but difficult. Cholinergic pathways are involved in these side effects, and donepezil, a cholinesterase inhibitor, may be useful for improvement of cognition. In this case report, we describe for the first time successful use of donepezil in treating cognitive deficits associated with maintenance ECT. The role of cholinesterase inhibitors in the treatment of cognitive deficits caused by ECT needs further studies.