Objective: Non-alcoholic fatty liver disease (NAFLD) negatively impacts on renal function with the contribution of the I148M variant in the patatin like phospholipase containing domain 3 (PNPLA3) gene. We hypothesized that children with prediabetes present with lower estimated glomerular filtration rate (eGFR) than those with normal glucose tolerance (NGT) and that the 148M PNPLA3 allele could play a worsening role. We aimed evaluating the influence of the I148M PNPLA3 polymorphism on the relationship between eGFR and prediabetes in children with obesity. Methods: One thousand thirty-six children underwent to complete assessment and were genotyped for the I148M PNPLA3 polymorphism. Results: Patients with prediabetes showed lower eGFR levels (171.03±40.32 vs. 190.80±41.71ml/min/1.73 m2; p=0.001) and higher prevalence of NAFLD (80% vs. 59%; p=0.003) than those with NGT. Children with prediabetes showed lower eGFR levels than those with NGT (150.97±14.56 vs 192.88±40.09; p