Fifty adult men with mild to moderate hypertension were recruited to participate in a double-blind crossover study. Each subject received 14 days of drug treatment and 14 days of placebo treatment (random order). Half the subjects were assigned to a metoprolol (150 mg/day) vs placebo treatment regimen and half to an atenolol (100 mg/day) vs placebo regimen. Blood pressure levels as well as measures of simple (proofreading), intermediate (visual-motor task), and complex (management simulation) task performance were obtained at the end of the drug and placebo treatment periods. Metoprolol treatment generated better scores than did placebo or atenolol treatment for proofreading, visual-motor performance, and several measures of complex managerial competence. Atenolol treatment generally resulted in performance levels that did not differ from those observed with placebo. However, atenolol-treated subjects made more errors than did placebo-treated subjects in the visual-motor task and also showed some deterioration on one measure of complex managerial functioning.