Endocrine disrupting chemicals (EDCs) are the substances which change the course of endocrine systems in a way that adversely affects the organism itself or its progeny. EDCs call for greater attention because of their increasing utility in daily products and possible correlation with compromised health.It has been reported that PCP is the most important degradation products of phenolic compounds due of its enhanced resistance towards biodegradation. Effect of Pentachlorophenol (PCP) on the histology of Liver of a fresh water Catfish Heteropneustes fossilis was studied by exposing the fish to 32ìg/l/day (1/10 of LC ) of sub lethal 50 concentration of PCPfor a period of 14 and 28 days. Histopathological changes observed in liver was vacuolization, necrosis, rupturing of hepatocytes th th during different time of exposure i.e., 14 and 28 days. In our present study PCP(32ìg/l/day) showed an adverse impact on liver of fresh water Catfish H. fossilis.