Nephropathy is the main cause of morbidity and mortality in patients with Type 1 diabetes and persistent microalbuminuria is the best marker of the consequent risk for its development in adults. In the paediatric population, puberty has long been recognised as a major risk period for the development of microangiopathic complications, although it is not necessarily associated with the progression to frank proteinuria. In fact, as many as 50% of subjects might revert to normoalbuminuria. Hypertension is a further risk factor and accelerates the progression of micro and macrovascular complications. There is evidence that angiotensin-converting enzyme inhibitors reduce renal damage by one or more mechanisms independent of their antihypertensive effects and they are the drug class of choice for the treatment of diabetic nephropathy. However, as angiotensin II receptor antagonists are more specific they might become the obvious treatment choice in the near future. There is no consensus on who should be treated with reno-protective drugs in the paediatric population, and when this should occur, due to the lack of a clear definition of the natural history of microalbuminuria in this age group. In this review controversial aspects of this issue are presented and discussed.