OBJECTIVE: Punarnavashtak kwath (PNK) is a classical Ayurvedic formulation, mentioned in Ayurvedic literature Bhaishajya Ratnavali, for hepatic disorders and asthma. This study investigated the hepatoprotective activity of PNK to validate the traditional use of this formulation. MATERIALS AND METHODS: PNK was prepared in the laboratory according to the method given in Ayurvedic literature. Phytochemical screening was performed to determine the presence of phytoconstituents. Hepatoprotective activity was evaluated against CCl(4)-induced hepatotoxicity in rats and by its effect on the HepG2 cell line. RESULTS: Preliminary phytochemical screening revealed the presence of alkaloids, tannins, flavonoids, saponins, and a bitter principle in PNK. Administration of PNK produced significant hepatoprotective effect as demonstrated by decreased levels of serum liver marker enzymes such as aspartate transaminase, serum alanine transaminase, serum alkaline phosphatase, and serum bilirubin and an increase in protein level. Thiopentone-induced sleeping time was also decreased in the PNK-treated animals compared with the CCl(4)-treated group. It also showed antioxidant activity by increase in activity of glutathione, superoxide dismutase, and catalase and by a decrease in thiobarbituric acid reactive substance level compared with the CCl(4)-treated group. Results of a histopathological study also support the hepatoprotective activity of PNK. Investigation carried out on the HepG2 cell line depicted significant increase in viability of cells exposed to PNK as compared with CCl(4)-treated cells. DISCUSSION AND CONCLUSION: It can be concluded that PNK protects hepatocytes from CCl(4)-induced liver damages due to its antioxidant effect on hepatocytes. An in vitro study on HepG2 cell lines also supports its protective effect.