We report a controlled 3-week study (n = 30) of adjunctive use of nadolol, 80 to 120 mg per day, vs. placebo for the management of violent psychiatric patients. There were no remarkable adverse cardiac effects at this dose. The active treatment group showed lower total Brief Psychiatric Rating Scale (BPRS) scores after the first week of treatment (analysis of covariance [ANCOVA], p less than .08) and similar trends for the activation factor and the hostility scale. There were parallel findings for measures of extrapyramidal symptoms (EPS) (Simpson-Angus Neurological Rating Scale), which were reliable after the second week (ANCOVA, p less than .02). A significant association between changes in EPS and BPRS scores was found by regression analysis, after the effects of baseline measures were removed. Given that nadolol does not penetrate the central nervous system well, the antiaggressive effects may be associated with sympathetic nervous system feedback mechanisms.