: A 56-year-old man suffered from severe diabetic ketoacidosis which was complicated by acute renal failure and rhabdomyolysis. Before admission the patient had had flu-like symptoms for 5 days and had developed polyuria and polydipsia. The clinical examination on admission showed his plasma glucose level was 80.65 mmol/L while the HbA1c was 7.4%. His amylase concentration was high without any signs of pancreatitis. The islet-associated autoantibodies (GAD antibody, islet cell antibody) were absent. These data were compatible with the diagnosis of fulminant type 1 diabetes. A continuous intravenous insulin infusion therapy was given during the acute phase to control hyperglycemia and ketoacidosis. This patient remained dependent on continuous veno-venous hemofiltration (CVVHF) for 5 days, followed by regular kidney dialysis for three times, before his renal function was finally recovered. To conclude, this is a rare case of abrupt onset fulminant type 1 diabetes with the onset of acute renal failure. Hence, early detection, quick diagnosis and immediate treatment are very important. In particular, prompt CVVHF and kidney dialysis are required and useful for rescuing the renal function.