Non-alcoholic fatty liver disease (NAFLD) occurs in patients with components of metabolic syndrome such as type 2 diabetes mellitus (T2DM). At present, the central pathophysiological problem in patients afflicted with NAFLD is insulin resistance. In this study, we aimed to determine the effects of a dipeptidyl peptidase-4 (DPP-4) inhibitor, teneligliptin, on the development of NAFLD in ob/ob mice. Five-week-old male ob/ob mice were divided into 4 experimental groups as follows: a group in which they were fed a high carbohydrate diet (HCD) for 8 weeks (n=8) as controls (control group 1), a group in which they were fed HCD supplemented with 0.018% teneligliptin for 8 weeks (n=8) (teneligliptin group 1), a group in which they were fed HCD for 12 weeks (n=8) as controls (control group 2), and another group in which they were fed only HCD for 4 weeks, and the HCD was then supplemented with 0.018% teneligliptin for 8 weeks (n=8) (teligliptin group 2). Hepatic steatosis was observed in all mice in the control group fed the HCD, but only mild hepatic steatosis was observed in teneligliptin group 1. Mice in teneligliptin group 1 fed the diet containing teneligliptin had lower hepatic triglyceride (TG) and free fatty acid (FFA) levels. Mice in teneligliptin group 1 exhibited improvement of insulin resistance; however, those in teneligliptin group 2 did not show any improvement of insulin resistance. Our results thus suggest that teneligliptin may be used as a preventative, but not as a treatment drug for the development of NAFLD.