Clarifying the cytochrome P450s (CYPs) changes in non-alcoholic fatty liver disease (NAFLD) is important for optimizing drug therapy. This study compared the expression of CYP isoforms in rat models of nonalcoholic fatty liver (NAFL) and non-alcoholic steatohepatitis (NASH). An NAFL model without tissue damage or inflammation was established by feeding rats a high-fat diet (HFD) for a relatively short period of 4 weeks. Feeding rats with a methionine-choline-deficient diet (MCDD) for 4 weeks produced steatohepatitis-like NASH. Here, the mRNA and protein expression levels of several CYP enzymes in NAFL and NASH models were compared with those in rats fed a control diet (CD). CYP1A2 expression and activity were upregulated in the NAFL model and downregulated in the NASH model, suggesting a reversal of CYP1A2 expression between NAFL and NASH. Differential expression of CYP1A2 in the NAFL and NASH models was observed in primary rat hepatocytes. These findings suggest that CYP1A2 expression/activity vary from the early stages of NAFL to NASH and that monitoring the pharmacokinetics of CYP1A2-metabolized drugs in humans with NAFL and NASH is necessary.