Idarubicin exhibits features rendering this drug unique among anthracyclines. The higher lipophilicity leads to faster accumulation in the nuclei, superior DNA-binding capacity and consequently greater cytotoxicity compared to daunorubicin. A major advantage over this reference drug is its ability to overcome MDR at least partially. Its major metabolite idarubicinol is as active as the parent compound and crosses the blood-brain barrier. Furthermore, idarubicin can be administered orally reaching sufficient plasma levels. Compared to other anthracyclines, the risk of cardiotoxicity as the main side effect for this group of drugs is reduced with idarubicin, when administered in a therapeutical dose. Thus, IDA has become an important drug in the treatment of acute leukemias and its potency in lymphomas, plasmocytomas and other solid tumors such as breast cancer is currently under investigation in several clinical studies.