The patient was a 51-year-old female. Post-biopsy arteriovenous fistula (AVF) and pseudoaneurysm in a renal allograft were diagnosed 5 yr and 4 months after she received a renal transplantation. Four years after the diagnosis, interventional treatment for the AVF and pseudoaneurysm was performed because of a high risk of pseudoaneurysm rupture. Although the longitudinal diameter of the pseudoaneurysm was more than 5 cm, this AVF and pseudoaneurysm were treated successfully by a percutaneous transluminal embolization, and renal function has remained stable after embolization. A selective interventional procedure proved effective for the large pseudoaneurysm in the renal allograft. Therefore, when a transcutaneous needle biopsy of the renal allograft is performed, although there are no apparent symptoms or signs of vascular complications during the clinical course, periodical examinations such as echo-Doppler imaging should be made on the allograft.