Justicia adhatoda (vasaka) leaves have long been used in Indian Ayurvedic system of medicine as antitussive. Its crude extract has been previously reported to have hepatoprotective activity. Vasicinone was isolated from leaves of J. adhatoda, column purified and characterized using, TLC UV, FT-IR and 1H NMR. The isolated vasicinone was evaluated for hepatoprotective activity using (CCl4)-induced acute hepatotoxicity model in mice. CCl4 treatments lead to significant increase in SGOT, SGPT, ALP levels. Pre-treatment with vasicinone and silymarin (25 mg/kg/day for 7 days) significantly decreased these enzyme levels. Histopathology of the livers from vasicinone and silymarin pre-treated animals showed normal hepatic cords and absence of necrotic changes suggesting pronounced recovery from CCl4 induced liver damage. Both vasicinone and silymarin significantly decrease the CCl4 mediated increase in pentobarbital indiced sleeping time in experimental animals, thus indicating recovery of liver function. Based on the above results it can be concluded that vasicinone may act as hepatoprotective in mice and warrants further investigation on human volunteers.