Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease that may progress to nonalcoholic steatohepatitis (NASH), hepatic tissue fibrosis, liver cirrhosis, and hepatocellular carcinoma. In this study, we investigated the effects of Pien Tze Huang (PTH), a well-known traditional Chinese herbal formula with liver protective effect, in methionine-choline deficient diet (MCD)- and high-fat diet (HFD)-induced NASH mouse models. Our results showed that PTH could exert hepatoprotective effects by improving liver weight and steatosis and reducing the fibrosis and serum levels of alanine transaminase (ALT) and aspartate transaminase (AST) in both animal models. The effects of PTH was accompanied with the reduction of infiltrated macrophages, the inhibition of the expression of cytokines, and the induction of adiponectin expression. Mechanistically, we found that PTH could inhibit the activation of proinflammatory transcription factor nuclear factor-κB (NF-κB) by preventing the degradation of inhibitor of κBα (IκBα). These results demonstrate that PTH can improve NAFLD largely due to its suppression of the NF-κB inflammatory pathway.