The efficacy and safety of lormetazepam (LMZ) and placebo were compared in 30 patients with sleep difficulties who were treated by general practitioners. During the three weeks of the study, each patient received placebo during either the first or last week and 1 mg/night of LMZ during the other two weeks. Neither patients nor physicians knew which week's medication was active drug and which was placebo. Twenty-three of the 30 patients completed the three-week trial. Both the quantity and the quality of sleep were significantly better during the weeks patients were given LMZ than during the week they used placebo. Physicians also rated the hypnotic performance as significantly better than that of placebo. Adverse reactions were evenly distributed among the LMZ and placebo treatment periods and were usually minor. Vital signs and laboratory values were unchanged during either treatment period. It is thus concluded that LMZ is a safe and effective hypnotic for use in general practice.