A single agent chemotherapy regimen, comprising epirubicin 120 mg m-2 iv at 21-day intervals for a maximum of six cycles was administered to 26 patients with intermediate or poor prognosis small cell lung cancer. Staging consisted of both conventional disease extent and prognostic guidelines based on laboratory parameters. The overall response rate was 57% which predominantly occurred among the intermediate prognosis group (14 of 17 patients), compared with only 1 of 9 patients in the poor prognosis category. Seven patients survived for at least 12 months, including one 3-year survivor (remains disease free). Chemotherapy toxicity was easily managed and chemoresponse was generally accompanied by an improvement in perceived performance rating. The study confirms the activity of epirubicin against small cell lung cancer and emphasizes the importance of patient selection within the spectrum of small cell lung cancer.