Effect of Hibiscus sabdariffa (is an edible medicinal plant, indigenous to India, China and Thailand and is used in Ayurveda and traditional medicine), leaf extract (HSEt) on the levels blood ammonia, and serum lipid profiles (cholesterol, triglycerides, phosphor lipids, free fatty acids) were studied for its protective effect during ammonium chloride induced hyperammonemia in Wistar rats. Ammonium chloride (AC) treated rats showed a significant increase in the levels of circulatory ammonia and lipid profiles. These changes were significantly decreased in HSEt and AC treated rats. Our results indicate that HSEt offers protection by influencing the levels of ammonia and lipid profiles in experimental hyperammonemia and this could be due to its (i) ability to detoxify excess ammonia, urea and creatinine, (ii) free radical scavenging property both in vitro and in vivo by means of reducing lipid peroxidation and the presence of natural antioxidants. Hence, it may be concluded that the hypolipidaemic and antihyperlipidaemic effects produced by the HSEt may be due to the presence of flavonoids and other polyphenolic compounds. But the exact underlying mechanism is remains to be elucidated.