Renal uric acid handling in 62 insulin dependent diabetic (IDD) patients of both sexes, without clinical or biochemical signs of nephropathy or hypertension was studied and compared to healthy age matched control groups. IDD adults (n = 38, age 45-64) presented uremia similar to controls (n = 9 age 45-64). Neither, the tubular charge or filtration charge (CFU) or the uric acid excretion fraction showed statistically significant differences. Young IDD (n = 24, age 13-37) presented levels uric acid than significantly (p less than 0.001) lowers to young controls (n = 10, age 13-38) and adults IDD (p less than 0.001). The CFU is lower in both, young and adult IDD when compared to young controls (p less than 0.02). Nevertheless, the CFU is higher in young IDD than in controls of the same age (p less than 0.001) or in adult IDD (p less than 0.001). In summary, we conclude the existence of an abnormal (uric acid) renal management caused by a tubular defect probably lying on the proximal tubular segment where the uric acid secretion is carried out.