Dermatomyositis is a disease of non-pyogenic inflammation of skin and muscles in which tissues and cells are damaged by pathogenic autoantibodies and immune complexes. Diffuse subcutaneous and interstitial muscular calcinosis is well recognised and common in childhood dermatomyositis. However, soft tissue calcification in a patient with adult onset dermatomyositis has been rarely reported. We have experienced a patient with adult onset dermatomyositis who had diffuse subcutaneous tissue calcification on hands, arms, chest, abdomen and buttocks.