Fish meat is considered one of the best protein source throughout the world. Being an animal of Water, it is always exposed to many harmful subtances and dangers. Out of these Mercury is one. As th substances come from various sources in various concentrations so affect the fish and other living things present in water ways. The present project was designed to study the Pathological effects of Mercury intoxication in Grass carp (A Fish specie used by human beings as diet). In this project,fish were artificially exposed to various concentrations of Mercury intoxication and comparative pathological effects were studied. It was concluded that such intoxication has multifarious effects on Fish meat.Hence it can be concluded that this very important diet source of meat is always at risk and some urgent measures must be taken regarding policy making in this respect.This project was first of it''s kind in this university i.e. UVAS,Lahore,Punjab, Pakistan.