Diabetic muscle infarction is a rare complication of diabetes. Since first reported in 1965, approximately 130 patients have been reported, with only 2 cases described affecting the upper extremity. We report on 3 men (age, 40-63) with diabetic muscle infarction involving the arm. The patients had symptoms 4 to 18 days before presenting to the emergency department and all required admission for their pain. Only 1 of the patients was febrile. The patients had type 2 diabetes mellitus for 10 to 25+ years, and 2 were on chronic hemodialysis, with the third starting peritoneal dialysis shortly after admission. Hemoglobin A1c ranged from 0.049 to 0.095. Creatine kinase levels ranged from 69 to 483 U/L and the white blood cell count ranged from 9.6 to 12.0 x 10(3)/microL. None of the patients required surgery nor had biopsies, and the patients were managed with rest, transdermal fentanyl, and later physiotherapy. Diagnoses were supported by MRI images in 2 patients and serial ultrasounds in the third patient. Although rare, the condition may be under-recognized. Pathophysiology, which may have some unique features in patients on hemodialysis, is briefly discussed.