The Patient was a male aged 59 with hemodialysis for 6 years given Warfarin as an anti-coagulant therapy after the implantation of artificial heart valve. Living related renal transplantation (Tx) was performed from his brother as a donor in Aug, 1997. Left kidney was removed, followed by reconstruction of renal arteries due to arterial anomaly on back table. Postoperatively, heparin was intravenously administered with Warfarin given orally again. Next day after Tx, he underwent re-operation to remove hematoma around the graft. Steroid pulse therapy was given under the diagnosis of acute rejection at the eight days after Tx. Moreover, muromonab (OKT3) was added for steroid-resistant severe rejection during which he required hemodialysis. At the 13 days after Tx, aneurysm was detected at the graft artery by ultrasound and gradually increased in size, followed by its resection at the 20 days postoperatively. At the 88 days, he discharged from our hospital with excellent graft function. We experienced a transplant recipient, accompanied by formation of renal pseudoaneurysm after the treatment of anti-coagulant therapy. For the patients given anti-coagulant therapy, unexpected formation of hematoma and pseudoaneurysm should be taken into consideration.