Objective: To investigate the crude extracts of Ichnocarpus frutescens (I. frutescens) for antiobesity effect. Methods: Leaves of I. frutescens were sequentially extracted with hexane, ethyl acetate, and methanol and their effect on viability of 3T3-L1 preadipocytes were evaluated. Based on this the apoptosis on preadipocytes was confirmed by DNA fragmentation and LDH (Lactate dehydrogenase) leakage assays. Anti-adipogenesis was performed by oil red O (ORO) staining and free glycerol release in the medium of differentiated adipocytes. Results: The hexane extract of I. frutescens (IFHE) inhibited cell viability in a time- and dose-related manner. An increased release of LDH, as a marker of membrane integrity, was observed at a dose of 200 μg/mL. The discontinuous DNA fragments on agarose gel electrophoresis showed the apoptotic effect of the IFHE. Morphological observations of cells stained with ORO showed a decrease in cellular lipid content at the concentrations tested compared to the induced control cells. In the experiment of lipolytic activity, treatment with IFHE enhanced glycerol secretion with the rates of approximately 28%, 55%, and 46% at the concentrations of 100, 200 and 300 μg/mL, respectively. Conclusions:The observed properties clearly revealed the medicinal property of I. frutescens in the treatment of obesity.