This report describes the case of a patient with peritoneal carcinomatosis due to recurrent adenocarcinoma of the ureter who was chemo-sensitive to weekly paclitaxel. A 73-year-old man was admitted to our hospital for pain in the right back in September 2009. Drip infusion pyelography(DIP)showed right hydronephrosis. Cytologic examination of the urine revealed many carcinoma cells in the urothelial tract. The patient underwent right nephroureterectomy, and examination of the resected specimen revealed a primary enteric-type adenocarcinoma of the ureter. Six months after surgery, he visited our hospital because of abdominal pain and distension. Abdominal computed tomography(CT)showed massive ascites. Cytologic examination of the ascitic fluid revealed many adenocarcinoma cells resembling those of the primary lesion. The patient received chemotherapy with S-1 as first-line treatment; however, he experienced severe anorexia and diarrhea. Subsequently, the patient received chemotherapy with uracil/tegafur(UFT)but abdominal distension worsened. Next, he received chemotherapy with weekly paclitaxel(80mg/m2 on days 1, 8, and 15, every 4 weeks). Thereafter, the ascitic fluid disappeared rapidly. After 6 courses of treatment with paclitaxel, abdominal CT revealed no ascitic fluid collection. The treatment was discontinued because of sensory neuropathy. Approximately 10 months later, the patient experienced massive ascites again. At 25 months after recurrence, he died of peritoneal carcinomatosis.