A 22-year-old Chinese male died in hyperglycaemic coma following a 36-h illness. The only significant pathological findings were in the pancreas where there was a heavy diffuse infiltrate of lymphocytes admixed with numerous eosinophils, macrophages and polymorphs. There appeared to have been massive, recent, synchronous necrosis of insulin-secreting B cells with no destruction of any other pancreatic parenchymal cells. The biochemical findings of severe hyperglycaemia, insulinopoenia, but a normal glycosylated HbA1 were compatible with an acute onset to the patient's diabetes. These features contrast with the very much slower destruction of B cells associated with insulitis seen in "classical" Type 1 (insulin-dependent) diabetes.