Background and Purpose Experimental Approach Diethyldithiocarbamate (DDC) is a major metabolite of disulfiram that is a potential drug for alcoholism treatment. In the present study, we attempted to explore the possible effect of DDC on non-alcoholic fatty liver disease (NAFLD) and related fibrosis in vivo. C57BL/6 mice and Sprague Dawley (SD) rats received a methionine/choline-deficient (MCD) diet to establish the model of NAFLD with or without DDC treatment. The livers and serum were assessed for histological changes and parameters related to lipid metabolism, liver injury, inflammation and fibrosis. Apoptosis and macrophage related markers were assessed by immunohistochemistry (IHC). Key Results Conclusion and Implications DDC significantly reduced hepatic steatosis in rats with NAFLD, induced by the MCD diet. DDC reduced the oxidative stress and endoplasmic reticulum stress-related parameters in mice with non-alcoholic steatohepatitis, induced by the MCD diet. IHC for Bax and cleaved caspase-3 showed that DDC inhibited the apoptosis of hepatocytes in the liver. DDC significantly reduced ballooning and Mallory-Denk bodies (MDB) in hepatocytes, accompanied by suppression of serum alanine aminotransferase, aspartate aminotransferase and MDB formation-related genes. DDC significantly alleviated hepatic inflammation, accompanied by suppression of inflammation-related genes. DDC suppressed the infiltration of macrophages, particularly inducible NOS-positive pro-inflammatory macrophages. In addition, DDC significantly alleviated liver fibrosis. Microarray analyses showed that DDC strongly affected lipid metabolism and oxidative stress-related processes and pathways. DDC improves hepatic steatosis, ballooning, inflammation and fibrosis in rodent models of NAFLD through modulating lipid metabolism and oxidative stress.