Obesity is caused by excessive adipogenesis and leads to metabolic diseases such as diabetes, hypertension, and degenerative arthritis. Therefore, there is an ever-increasing need to identify new anti-obesity compounds. In this study, the anti-obesity effects of (E)-3-(4-(tert-butyl)phenyl)-N-isobutyl-2-methylacrylamide (BPIMA) were evaluated using pre-adipocytes and a high-fat-fed C57BL/6J mouse model. As the results, BPIMA effectively inhibited adipocyte differentiation (64.3% at 40 μM) without exhibiting any cytotoxicity. Additionally, BPIMA decreased the protein levels of PPARγ, FAS, C/EBP, and SREBP in 3T3-L1 cells in a concentration-dependent manner. In C57BL/6J mice, a significant decrease in body weight, adipose tissue, and fatty liver was observed in the BPIMA-treated high-fat group compared to that observed in the vehicle-treated high-fat group; the serum levels of total cholesterol and glucose also significantly decreased in the BPIMA-treated high-fat group. Moreover, the weight and fat level of liver and serum AST, ALT activity in the BPIMA-treated high-fat group were similar to low fat diet-control group. These findings show that BPIMA may be a potential anti-obesity compound.