Abstract: A Common Indian cat fish, Clarias batrachus Linneaus was treated with Lead Acetate for sub-acute and chronic exposure to the xenobiotic. The sub acute study included 3 days and 7 days exposure to different concentrations of lead acetate, while chronic study included exposure to 15 ppm lead acetate for 105 days. In all the cases tissues from Gills, Bones, Liver, Blood, Kidneys, Muscles, Skin and GI tract were removed and analyzed by AAS to find lead accumulation. The Bio-Concentration Factor (BCF) was calculated .The BCF varies from organ to organ. Additionally, X-rays photography was made on the chronic treated fishes from time to time, to see whether skeletal tissue is a target of the heavy metal or not. The Co-relation Co-efficient ( r’) in these tissues between Lead treatment and Lead accumulation was found to be highly significant suggesting it both as a dose-dependent and time-dependent process.