Epirubicin (4'-epidoxorubicin), a diastereoisomer of doxorubicin, has established activity in the treatment of many cancer types sensitive to doxorubicin. Its activity in other tumor targets such as melanoma, head and neck cancer, and recurrent colorectal cancer has been less well defined. Three concurrent phase II studies examined the efficacy and toxicity of epirubicin (90 mg/m2 given intravenously at 3-week intervals) in the treatment of 71 patients with the aforementioned cancers. Of 66 eligible patients who were assessable for response, one patient (with colorectal cancer) achieved a complete response and three patients (with head and neck cancer) achieved partial responses. The response rate in patients with head and neck cancer was 18% (95% confidence interval, 4-43%). Myelosuppression, alopecia, and nausea were the most frequent toxicities. Two patients died of neutropenic sepsis and grade IV leukopenia occurred in six patients (8%). Grade III toxicities were as follows: leukopenia (17%), anemia (10%), alopecia (8%), fever (1%), thrombocytopenia (1%). Grade I or II cardiac toxicity was noted in four patients at cumulative doses ranging between 375 mg/m2 to 1,283 mg/m2. Epirubicin is ineffective as a single agent at this dose and schedule in the treatment of patients with melanoma and colorectal cancer. In head and neck cancer, a modest response rate encourages further exploration of epirubicin and related anthracyclines in combination regimens.