A 53-year-old black male with no history of neuropsychiatric behavioral problems was treated successfully with propranolol, furosemide, and minoxidil for previously uncontrolled hypertension. However, paranoid ideations, illusions, severe combativeness, and visual hallucinations developed shortly after initiation of the listed therapy. When atenolol was substituted for propranolol, all psychotic behavior resolved.