We tested the possible role of epirubicin, 100 to 130 mg/m2 administered i.v. every 3 weeks, in patients with advanced adenocarcinoma of the rectum untreated with chemotherapy. Sixteen of 17 entered cases were evaluable. No complete or partial responses were observed. The median time to progression was 6 weeks, and the median survival was 36 weeks. Reversible leukopenia was the major toxic side effect. The median epirubicin cumulative dose was 330 mg/m2; no patient had clinical cardiac toxicity. With no responses recorded in 16 evaluable patients, the activity of epirubicin in rectal cancer ranged between 0 and 18%, with 95% probability. Further studies with epirubicin in this tumor are not indicated.