A multicentre Phase II study of epirubicin has been performed in patients with measurable or evaluable recurrent or metastatic transitional cell bladder cancer. Epirubicin was given intravenously every 3 weeks at a dose of 100 mg/m2. An objective response rate of 28% was observed (one complete and nine partial remissions) in an evaluable group of 36 patients, (confidence interval 15%-45%). Subjective improvements in the condition of patients were seen in responding and 'no change' patients. An interesting observation was the good response seen in patients with recurrent bladder disease who had previously received radial radiotherapy. Toxicity was considered to be acceptable and manageable, the most frequent being alopecia, and nausea and vomiting. Haematological toxicity was slight. One patient developed skin pigmentation, a not previously recognized complication of epirubicin treatment. Three cases of possible cardiotoxicity were seen in the 43 patients evaluable for toxicity. Epirubicin in thus an active agent in transitional cell carcinoma of the bladder, with a role as a single agent for palliation. It may also be useful in combination regimens for more aggressive treatment.