The aim of this study was to identify the effect of fermented Angelica gigas Nakai (A. gigas) on lipid metabolism in orotic acid-induced fatty liver model rats. Sprague-Dawley male rats were randomly divided into four dietary groups (n=6 per group): a normal (N) group fed a standard diet only, OA control, OA acid plus 5% (w/w) A. gigas (OAG), and OA plus 5% (w/w) fermented A. gigas (OFAG). OA treatment induced enlargement of the liver and accumulation of hepatic triglycerides. The consum ption of fermented A. gigas reduced triglyceride concentrations in the liver and increased the serum lipid concentrations to normal levels. Furthermore, OA treatment significantly decreased serum triglyc eride concentrations without diminishing mRNA expression of microsomal triglyceride transfer protei n (MTP) and protein disulfide isomerase (PDI). Hepatic MTP mRNA expression increased 1.08-fold in response to OA treatment, despite triglyceride accumulation in the liver relative to that of the normal group. OFAG administration was slightly lower as compared to the OA treatment. This result suggests that MTP mRNA expression is not always correlated with hepatic triglyceride accumulation in the OA-induced fatty liver model. However, PDI mRNA expression was significantly increased in the OAG and OFAG groups (1.62-fold and 1.63-fold, respectively) compared with the normal group. The hepatocytes in the OA group contained numerous large fat droplets. These were slightly reduced in the OFAG group.