Although pu-erh tea has been shown to suppress hyperlipidemia, it is unclear how it modulates fatty acid synthase expression in mice fed on a high-fat diet. We investigated the effects of a pu-erh tea extract (PTE) on diet-induced body fat accumulation. C57BL/6J mice were fed a control diet, a high-fat diet (HFD), and HFD supplemented with 0.225% or 0.45% PTE for 70 d. Supplementation with PTE reduced the body weight gain, and the abdominal and liver fat accumulation. A significant difference in the triglyceride level were observed between the HFD control and HFD+0.45% PTE groups. A PTE intake tended to decrease sterol regulatory element-binding protein (SREBP)-1c and fatty acid synthase (FAS) mRNA expression in the liver of the mice. These findings indicate that PTE reduced lipogenesis by down-regulating SREBP-1c and related molecules, leading to the suppression of body fat accumulation.