Diabetic muscle infarction(DMI) is an uncommonly reported complicatian of diabetes mellitus, DMI tends to occur in younger, poorly controlled diabetic patients with other end organ complications(retino- pathy, nephropathy, neuropathy). The typical feature of DMI is abrupt onset of thigh pain, tenderness, and swelling, over a period of days, and a firm mass develops. There are no associated systemic symptoms or signs indicative of infection and no skin disco- loration suggestive of cellulitis or thrombophlebitis. The patient was diagnosed as DMI with the findings of ultrasonographic, bone scan and magnetic reson- ance imaging as well as typical clinical and labora- tory findings. The painful mass persists for weeks, occasionally with exacerbation of symptoms, and then spontaneously resolves over several montks. Immo- bilization of the extremity with prolonged bed rest and strict sugar control has had beneficial results. We report a case of diabetic muscle infarction in a 30- year-old woman with insulin dependent diabetes mellitus