Mitoxantrone is useful for the treatment of cancer and MS and, as with other chemotherapeutic agents, many studies have examined its tolerability. The suitability of mitoxantrone in MS is particularly interesting because of its role in treating various stages of the disease. Evidence shows that mitoxantrone could be a first-line treatment for malignant forms of MS, and a second-line drug in relapsing-remitting or secondary progressive MS that is unresponsive to interferon beta-1a, -1b or glatiramer acetate. Mitoxantrone should, however, be restricted to patients with demonstrable inflammatory disease activity, and should only be prescribed by neurologists with previous experience in both MS and mitoxantrone therapy. This review examines the properties of mitoxantrone, its tolerability, and discusses its suitability for treating various forms of MS, referring to several important studies.