In 1990, 81 children and adolescents with insulin dependent diabetes were studied for early signs of diabetic nephropathy. Nine patients were identified as having microalbuminuria (incipient nephropathy). These subjects were re-examined three years later. In five of these cases, the second examination revealed normal albumin excretion; in three of the four cases in whom microalbuminuria persisted, the rate of albumin excretion had decreased. The general improvement in albumin excretion rates in the initially microalbuminuric group could not be explained by improved glycaemic control nor interventional drug treatment. The lack of progression in this microalbuminuric group from the original prevalence study suggests that this method of identifying early nephropathy in childhood may not be valid or that the progression of incipient nephropathy in childhood is more irregular or slower than in later life.