Background: Paclitaxel (Taxol) has been shown to be effective in metastatic bladder cancer as single agent and in combination with other cytotoxic drugs. Its efficacy seems to be comparable to cisplatin. We have used paclitaxel as alternative to cisplatin in selected patients with simultaneous radiochemotherapy. The objective of this article is to summarize the preliminary results with regard to feasibility and toxicity. Patients and Methods: From 10/97 through 10/98 7 patients with locally advanced or recurrent urothelial bladder cancer were treated with radiotherapy and simultaneous paclitaxel ± cisplatin. All patients had macroscopic irresectable residual tumor after transurethral surgery or cystectomy. Paclitaxel was given twice weekly in a daily dosage of 25 through 35 mg/m2 as 1-hour-infusion. Cisplatin was given in a dosage of 25 mg/m2 daily on days 1 to 5. Results: All patients completed the scheduled therapy regimen. The acute toxicity consisted mainly of enteritis (Grade I to II CTC). As severe toxicity, 1 severe skin reaction in the groins (Grade III) after 20 Gy and 1 Grade-III enteritis were noted. Both patients with severe complications recovered within 4 weeks after treatment. Hematological toxicity was mild to moderate in all cases. Conclusions: This report suggests that paclitaxel is a promising agent for simultaneous radiochemotherapy protocols. The clinical value remains to be better defined especially the question whether paclitaxel may improve the results if used as alternative to standard cisplatin. At the moment paclitaxel offers at least an attractive alternative to cisplatin in patients with impaired renal function.