Interferon alfa (IFN-α) was recently introduced for the treatment of cutaneous malignancies, benign tumors, and immunological disorders, and it has definitely broadened our therapeutic spectrum. Its adverse effects have been classified into acute, subacute, and chronic reactions. Acute reactions, such as fever and flulike symptoms, are usually self-limiting, while chronic neurologic and psychiatric disorders may cause significant morbidity.1 Herein we describe 4 female patients who developed persistent myopathic symptoms during prolonged recombinant interferon alfa (rIFN-α) therapy.