Interferone-α is used recently in the treatment of hematologic malignancies as well as viral hepatitis. Occurrences of various adverse effects associated with IFN have been reported increasingly. We report here in a case of patient who developed diverse clinical symptoms in various organs such as heart, liver, kidney following long-term IFN therapy for chronic myelocytic leukemia. The autopsy revealed the pathological changes in various tissues such as the heart muscles, the renal glomeruli and the skeletal muscles, which were confirmed by transmitted electron microscopy. The possible roles of IFN-α in those tissue damages are discussed.