PURPOSE: To determine whether propranolol can decrease surgical tremor and anxiety in residents performing ocular microsurgery without impairing patient or physician safety. METHODS: In this randomized, double-masked, crossover study, 5 third-year ophthalmology residents ingested a capsule containing either propranolol, 40 mg, or placebo 1 hour prior to performing ophthalmic microsurgery. All residents were healthy men under age 30 years. Prior to commencement of the study, all participants had successfully been administered a test dose of propranolol without side effects. The study took place over a 10-week period. At the conclusion of each case, both the resident and attending surgeon observer independently completed a form grading, on a sliding scale: (1) amount of overall tremor; (2) amount of tremor during placement of the first 3 sutures after lens or nucleus extraction; (3) anticipated difficulty of the case; (4) actual difficulty with the case; and (5) anxiety (surgeon only). In addition, the type of procedure performed, complications encountered, and surgeon side effects were recorded. The data were analyzed with a 2-way analysis of variance for unbalanced data. RESULTS: A total of 73 surgical cases were performed; the surgeons were administered propranolol for 40 cases and placebo for 33. As judged by the resident surgeon, there was a highly significant effect of propranolol in decreasing anxiety (P = .0058), reducing surgical tremor overall (P < .0001), and reducing tremor while placing the first 3 sutures following lens extraction (P < .0001). There was no treatment-by-surgeon interaction for any of the measures. Complications and difficulty of the case, as judged by both the resident and attending surgeons, were not significantly different in the propranolol versus placebo groups (P > .05). There were no side effects reported or observed in any of the surgeons. CONCLUSIONS: Propranolol, 40 mg, administered 1 hour prior to surgery, significantly decreases tremor and anxiety in the surgeon without untoward effects to the surgeon and the patient. However, it is unknown whether decreased tremor and anxiety improved surgical outcome.