Diabetic kindney disease affects up to one third of patients withtype 1 and type 2 diabetes and is anow the commonest single cause of end‐stage renal failure in the western world. The cumulative incidence of diabetic nephropathy continues to increase as type 2 diabetes becomes more prevalent. Managing increasing numbers of patients requiring renal replacement therapy is a major challenge for health services throughout the world. Diagnosis is usually made upon clinical grounds and is based on the detection of albuminuria. If the diagnosis is in doubt renal biopsy should be considered. The major clinical phases of diabetic kidney disease are microalbuminuria, proteniuria or overt nephropathy, progressive renal impairment, and end‐stagerenal failure. Not all patients progress to end‐stage renal afailure because of an associated excess cardiac mortality. Major risk factors for diabetic kidney disease are poor glycemic control and hypertension. Genetic factors also appear to play an important role in determining an individuals predisposition, but the gene(s) responsible have not yet been unequivocallly identified. Treatment is based upon primary prevention with good glycaemic control and treatment of hypertension. Secondary prevention with antihypertensive therapy, particularly with agents acting on the renin‐‐angiotensin system, can slow the rate of progression of diabetic nephropathy and delay the onset of end‐stage renal failure. Coexisting cardiovascular risk factors should also be aggressively managed. Patients with advanced diabetic kidney disease often have multiple problems that require the input of a large number of health care professionals.