Abstract Background Diabetic nephropathy is considered a major complication among patients with type 1 diabetes. In the present study, we aimed to evaluate urinary N-acetyl-beta-D-glucosaminidase levels (uNAG) in patients with type 1 diabetes mellitus (DM). Methods This cross-sectional study of 60 patients with type 1 DM, was categorized into two groups (normoalbuminuria and microalbuminuria) and 30 healthy controls. uNAG was measured in all cases and controls. Results Patients with type 1 DM showed increased mean uNAG values compared to controls. Interestingly, increased NAG levels were found in diabetic patients without early signs of glomerular damage (normoalbuminuric). The severity of renal disease, poor glycemic control, and duration of diabetes were all proportional to uNAG increased levels. Conclusions NAG measurement is a useful, noninvasive tool for assessing renal involvement in children with diabetes and for early diagnosis of developing nephropathy.