Two groups of anxious patients were treated with either clorazepate (n equals 27, 15 mg at night), or diazepam (n equals 27, 5 mg three times a day), and the anxiolytic effects of the treatments compared during a 22 day period. Both drugs were effective antianxiety agents (as assessed by the Hamilton Anxiety Scale, Analogue and Rapid Symptom Check List scales). The response to drug treatment did not differ according to the type of anxiety, psychological or somatic. No significant difference was observed between the two drug treatments. Separation of patients according to their anxiety type did not change this finding. Clorazepate, when administered as a single dose at night, is an effective short term anxiolytic.