A 51-year-old man was admitted with microscopic hematuria at 10 years after living donor renal transplantation. In order to distinguish between acute tubular necrosis and acute rejection, a graft biopsy was performed under ultrasound guidance at 1 month posttransplantation. Doppler sonography revealed 3 pulsatile cystic masses and an arteriovenous fistula (AVF) in the lower kidney pole. Selective transplant renal angiography revealed 3 pseudoaneurysms with an AVF supplied by a lobular artery in the lower pole. The diagnosis was AVF with pseudoaneurysm, which developed secondary to percutaneous renal allograft biopsy. Interventional treatment was performed because of the high risk for pseudoaneurysm rupture. The AVF and pseudoaneurysms were treated successfully by percutaneous transluminal embolization; renal function remained stable after embolization.