The computer-ordering system (COS) database was used to investigate hypnotic prescriptions issued to outpatients at various medical departments at the Dokkyo University School of Medicine. Hypnotics were prescribed for 3428 patients (1613 men, 1815 women), with a mean age of 56 years (range 8-91 years). The number of prescriptions was 3.5% of the total number of prescriptions (123 518). Although hypnotics were prescribed most often to patients in their 60s, generally, the incidence was higher for younger-aged patients. Physicians in all specialty areas tended to prescribe short-acting benzodiazepine hypnotics. The issuance of hypnotic prescriptions should be investigated to determine the prevalence of insomnia in various medical specialties.