Coronary bypass surgery in a patient with functioning renal graft was reported. Surgery was carried out using standart operative techniques providing some precautions for renal graft protection: i. e. adequate mean perfusion pressure, volume replacement, and renal outflow during cardiopulmonary bypass, and appropriate prophylactic antibiotic and immunosuppressive therapy. Postoperative course was uneventful and blood urea nitrogen and serum creatinine levels were comparable to the preoperative levels. Three months after the operation he was found to be asymptomatic.