A double-blind crossover comparison is reported of the effects of alprazolam and placebo on anxiety and angina in 27 ambulatory outpatients with angina pectoris stabilized on propranolol. Alprazolam was shown to be a safe treatment when combined with propranolol in these patients. Patients receiving alprazolam with propranolol reported more improvement on their targeted symptoms than did patients receiving placebo with propranolol. The side effect most often reported was moderate drowsiness or sedation; no unusual side effects emerged. There was no evidence that alprazolam compromised the patients' response to propranolol.