The dose-limiting toxicity of the widely used anticancer agent, doxorubicin, is a destructive, irreversible and progressive cardiomyopathy. Prevention of this cardiotoxicity without reduction of antitumour efficacy or the production of new toxicities has therefore been a long-time therapeutic goal. It has now been largely achieved by prior administration of dexrazoxane (DXRz; Cardioxane in Europe; Zinecard in North America; ICRF 187). Six randomized, controlled clinical trials in breast and lung cancer and in soft tissue sarcomas of children have shown a 90% reduction in doxorubicin-induced cardiotoxicity. The results of all these trials lead to the conclusion that DXRz permits: (1) cardiotoxic doses of doxorubicin to be given without cardiotoxicity; (2) patients with increased cardiac risk factors to be treated with full doses of dioxorubicin; (3) second-line treatment with other cardiotoxic drugs.