In the present study, the effects of environmental pollution on aquatic vertebrates of two Ramsar Sites viz. Haleji and Keenjhar Lakes were noted and inventories of the vertebrate fauna were prepared. In the water samples taken from Haleji Lake, the pesticides of organophosphate (OP) and organochlorine (OC) groups were estimated above the Maximum Acceptable Concentrations (MAC). These concentrations were much higher in muscles and fat contents than other tissues of birds. All water samples from Keenjhar Lake contained pesticides below the MAC level. A total of 22 species of mammals, 228 species of birds, 32 species of reptiles, 2 species of amphibia, 37 species of fishes and 33 species of plants were recorded from Haleji Lake, while, 25 species of mammals, 121 species of birds, 29 species of reptiles, 2 species of amphibia, 54 species of fishes and 258 floral species were recorded from the Keenjhar Lake. The research techniques and information are helpful for graduate and research students of Biological Sciences, Environment Science and wetlands managers.