ABSTRACT In this single-blind study the sedative and hypnotic properties of buspirone, a nonbenzodiazepine anxiolytic, were investigated in 8 anxious outpatients. Polysomnographic recordings were gathered during baseline, at the start of active medication, after 3 weeks of treatment and one night after discontinuing treatment. Daytime alertness was measured using the Multiple Sleep Latency Test and performance tests. The effects of buspirone on sleep structure were minimal and of no clinical consequence. Subjectively, the patients reported improved sleep quality. There were no effects on daytime alertness at the beginning, after 3 weeks or at sudden discontinuation of the medication. It is concluded that buspirone does not have a sedative or hypnotic effect in anxiety patients.