['Growing evidence suggests that not only type 2 diabetes (T2D) but also prediabetes (PD) is common in patients with non-alcoholic fatty liver disease (NAFLD). However, few data exist on how PD impacts the histological characteristics of NAFLD patients. In this exploratory study, we sought to investigate the associations of PD and T2D with the severity of the histological features in patients with NAFLD.', 'The population consisted of 280 patients with biopsy-proven NAFLD. The associations of PD and T2D with the severity of histological features of NAFLD were analyzed using multiple logistic (or ordinal logistic) regression models after adjustment for confounding factors.', 'PD and T2D was noted in 102 (36.4%) and 92 (32.8%) of patients, respectively. Of the 92 patients with T2D, ten (10.9%) were diagnosed de novo after the OGTT. PD and T2D were significantly associated with more severe portal inflammation (P<0.01); the adjusted odds ratios (ORs) of PD and T2D for having a higher grade of portal inflammation were 1.8 [95% CI, 1.1, 3.2] and 2.6 [95% CI, 1.3, 5.8]), respectively. A similar relationship was observed for liver fibrosis (P<0.001); specifically, the adjusted ORs of PD and T2D for having a higher grade of hepatic fibrosis were 2.4 [95% CI, 1.3, 3.7] and 3.8 [95% CI, 1.9, 6.1]), respectively.'] Is not only type 2 diabetes but also prediabetes associated with portal inflammation and fibrosis in patients with non-alcoholic fatty liver disease?