The aims of this study were to document the toxicity of systemic chemotherapy and response rates in patients with ureteric obstruction caused by urothelial cancer. The study group included 91 patients who received cisplatin and methotrexate; 36 (40%) had upper tract dilatation, 9 of whom had drainage by stenting or nephrostomy and 55 (60%) had normal upper tracts. The response rate was documented in 65 patients (71%) who had measurable primary or metastatic disease. No significant differences were found between the dilated/drained group, the dilated/undrained group and the normal group in biochemical measurements of renal function during or after the courses of chemotherapy. Serious haematological toxicity occurred in 10% (10/104 cycles) of the dilated/undrained group and in 6% (12/200 cycles) of the normal group. The complete response rate in the dilated group was 15% compared with 41% in the normal group. No increased chemotherapy toxicity was observed in patients with upper tract dilatation and a significant complete response rate was found in patients with upper tract dilatation without renal impairment.