We report two cases of spontaneous urinary rupture caused by primary ureteral or renal pelvic cancer. Case 1: A 76-year-old man presented with macrohematuria and left back pain. Magnetic resonance imaging showed left middle ureteral tumor and rupture of upper ureter. Left nephroureterectomy was performed. Histological findings revealed urothelial carcinoma, G2, pT1, lt-u0, ew0, ly0, v1. At five months postoperatively, he died of lymph node metastases after two courses of adjuvant chemotherapy. Case 2: A 59-year-old man presented with macrohematuria and left back pain. Computer tomography showed left renal pelvic tumor with extravasation of urine. Left nephroureterectomy was performed. Examination of surgical specimen revealed a renal pelvic tumor and rupture hole at the renal pelvis. Histological finding revealed urothelial carcinoma, G3, pT3, lt-u0, ly0, v1. One course of adjuvant chemotherapy was performed. At six months postoperatively, he was free from recurrence.