Fat cells or adipocytes are important sites in glucose metabolism where triglycerides are synthesised from the excessive glucose in blood. These cells are produced from a complex process called adipogenesis where pre- adipocytes are differentiated by chemical inducer into mature adipocytes. Herbs and plants have shown tremendous effects on adipogenesis. Eugenia polyantha is a tropical plant that has been used in Asian culinary preparations as well as traditional medicine in treating diabetes, arthritis and cardiovascular diseases. In this study, we examined the effect of water extract of Eugenia polyantha on 3T3-L1 cells differentiation in the presence and absence of insulin. Result shows that water extract of Eugenia polyantha alone failed to enhance differentiation, but addition of 1 µg/mL of insulin significantly increased the formation of adipocytes. Ten days treatment with Eugenia polyantha significantly increased the triglyceride content as measured by Oil Red O assay and glucose utilisation in medium by dose dependent manner. Intracellular CEBP-a, adiponectin and GLUT4 proteins were also expressed significantly during the treatment of low concentration of Eugenia polyantha. This study provides the first evidence of Eugenia polyantha sensitising effect on 3T3-L1 adipogenesis process by enhancing the expression of CEBP-a, adiponectin and GLUT4 proteins.