We report here a case of interstitional pneumonia (IP) associated with amyopathic dermatomyositis (DM). In August, 1998, a 53-year-old Japanese man was admitted to our hospital because of fever, polyarthritis and erythematous heliotrope eruption and Gottron's sign without any symptom of myositis. Serum CK level and EMG were normal. Jo-1 antibody was negative. Chest computed tomography (CT) revealed IP at both lung base areas. The patient was diagnosed as amyopathic DM with IP. When IP rapidly progressed, methylprednisolone pulse therapy and oral high dose prednisolone were not effective. High-dose intravenous cyclophosphamide seemed to be transiently effective, but oral cyclosporine A was not effective. The patient was died of respiratory failure in October 1998. During the course, we measured serum levels of LDH, sIL-2 R, s-ICAM-1 and KL-6, KL-6 could be a sensitive parameter of IP activity.