In vitro anticancer and anthelmintic properties of the phytostilbene (+)-α-viniferin had been established. However, contradictory reports are available about the mode of action of the chemical. Therefore, an in vivo investigation was carried out to see whether or not the cell cycle arrest is the cause of cell death in the albino mice exposed to (+)-α- viniferin. Cell cycle was analysed in the liver cells of albino mice treated with different concentrations of the phytochemical, through flow cytometer. The results showed a constant dose dependent (1 mg to 5 mg (+)-α- viniferin/kg body weight of mice) increase in number of cells in the SubG1 stage of cell cycle along with a steady decrease in the number of cells in G0/G1 phase. Thus no cell cycle arrest was evident in any phase of cell cycle in the mice exposed to different concentration of (+)-α-viniferin. The flow cytometric results were also supported by histochemical observations of large number of dead cells in the liver section of mice in vivo exposed to (+)-α- viniferin. An increase in cell death with an increase in the doses of the phytochemical as observed in the present study need to be study further to elucidate the mechanism of action of the compound leading the death of the liver cells in mice.