The plant phenolic compounds such as flavonoids play an important role in the protection of several disorders. Some of the plant derived compounds possess potent hepatoprotective efficacy. The present study was designed to assess the prophylactic effect of Hibiscus rosa sinensis (HRS) extract against thioacetamide (TAA) induced hepatotoxicity in male wistar rats. TAA treated showed noticeable hepatotoxicity symptoms marked by suppression of antioxidant armoury and destruction of liver morphology. It resulted in an elevation of serum hepatotoxicity markers such as aspartate aminotransferase, alanine aminotransferase and lactate dehydrogenase activity. However, oral pretreatment with HRS at lower (100 mg/kg b.wt.) and higher dose (200 mg/kg b.wt.), was given to rats for 14 consecutive days, showed significant reduction in the activity of enzymes viz; catalase, xanthine oxidase, glutathione peroxidase, glutathione reductase, quinone reductase and in the levels of reduced glutathione. Moreover, HRS extract significantly ameliorated TAA mediated liver injury possibly by inhibition of lipid peroxidation, restoration of endogenous enzymatic defense system and effective in preventing the development of hepatotoxicity. Histopathological examination also revealed marked recovery in pretreated groups. The protective effects of the extract could be due to the presence of polyphenolic content. Quercetin being one of its major components therefore the protective effect may be attributed on the quercetin as well as its synergistic effect with other polyphenols. The results indicate the antioxidant properties of HRS extract against TAA induced biochemical alterations.