A case of spontaneous peripelvic extravasation associated with primary ureteral tumor is reported. A 56-year-old woman presented with left flank pain. Excretory urogram and abdominal computed tomographic (CT) scan demonstrated left hydronephrosis with extravasation of contrast materials around the renal pelvis. Retrograde pyelogram showed the filling defect in the left upper ureter. Under diagnosis of ureteral tumor, total nephroureterectomy was performed. Histological findings revealed transitional cell carcinoma. 80 cases of spontaneous peripelvic extravasation in Japan were reviewed and discussed briefly.