Epirubicin (4'-epidoxorubicin), an analogue of doxorubicin (Adriamycin), has established activity in the treatment of small-cell lung cancer (SCLC) when used at doses of 75 to 120 mg/m2 in previously untreated patients. We completed a phase II study of epirubicin (85 mg/m2 given intravenously at 3-week intervals) in 20 patients with recurrent SCLC, all of whom had received prior combination chemotherapy. Of 19 patients who were assessable for response, 2 achieved a complete response and 2 a partial response, for an overall response rate of 4/19 (21%); 95% confidence interval, 8%-43%). Myelosuppression and alopecia were the most frequent toxicities; epirubicin was otherwise well tolerated, with other toxicities such as nausea and vomiting being infrequent or mild. Epirubicin at a dose of 85 mg/m2 exhibits modest single-agent activity in previously treated SCLC and is generally well tolerated. Given as a single agent or in combination with other well-tolerated drugs, epirubicin would be suitable in cases in which palliation of symptoms without undue toxicity is required in the management of previously treated SCLC.