We evaluated the efficacy of epirubicin in a phase II trial in breast cancer, as well as its cardiac toxicity. The study was carried out on 40 female patients with advanced, metastatic, or recurrent breast cancer. The patients were grouped into two groups: group I received 30 mg/m2 epirubicin weekly, and group II 90 mg/m2 epirubicin every 3 weeks. Cardiac monitoring was by ECG, roentgenography, echocardiography and endomyocardial biopsies. Clinical results were 35.3% overall response in group I, and 50% overall response in group II. No untoward cardiac toxicities were encountered. We conclude that epirubicin is an effective agent in breast cancer with relatively little cardiac toxicity.