Doxorubicin is an essential component of the treatment of aggressive lymphoma, childhood solid tumors, bone and soft tissue sarcomas, and breast cancer and additional indications are emerging. On the other hand, daunorubicin has occupied the central position of interest in the treatment of acute leukemia. Epirubicin has a spectrum very similar to doxorubicin but lesser toxicity. The ability to protect against cardiotoxicity with ICRF-187 further enhances clinical interest in exploiting modifications in doze intensity to therapeutic advantage. Idarubicin has at least equivalent activity to daunorubicin and doxorubicin in leukemia. New areas of research in relation to anthracycline antibiotics include introduction of new the analogs, insight into mechanisms of resistance, the reversal of multidrug resistance in vitro, the protection of cardiac toxicity, and the study of other important biochemical reactions relevant to cytotoxicity. Orally active anthracyclines such as idarubicin and compounds which lack cross-resistance with the parent drugs or have other mechanisms for cytotoxicity are being developed. It is likely that these modifications will lead to an expanding therapeutic spectrum for these already widely useful drugs.