Current guidelines necessitate varying degrees of long-term anticoagulation in patients with mechanical heart valve(s) to prevent thrombotic and embolic complications. We describe a patient with a functioning aortic mechanical valve without anticoagulation for 23 years. A 68-year-old man had an aortic valve (St Jude Medical) replacement in 1984. His native valve was incompetent from infective endocarditis. He discontinued Coumadin three months after the surgery. He presented 23 years later with palpitations for one month. Further work-up revealed a NYHA class I function, normal sinus rhythm, normal sized heart on chest X-ray, normal systolic and diastolic function on echocardiography. Mean transaortic gradient was 19 mmHg and calculated valve area was 1.48 cm(2). Fluoroscopy showed normal excursions of the mechanical aortic valve. Exercise stress test did not show any limitation in effort tolerance or perfusion defects. He was discharged on daily aspirin and clopidogrel.