A 16-year-old boy with insulin-dependent diabetes mellitus since age five years was admitted with severe ketoacidosis, and suffered a cardiorespiratory arrest from which he made a full recovery. He subsequently developed the typical clinical picture of diabetic amyotrophy with painful asymmetrical weakness and wasting of proximal lower limb muscles. Cerebrospinal fluid protein was elevated, and electromyography showed typical changes. Diabetic amyotrophy has not previously been reported in this age group.