Crocodile plays key role in maintaining the ecological system all over the world. They are not only helpful in controlling the population of rodents but also helpful for humans by stopping the spread of diseases. They equally support to prevent river blindness. Juveniles of crocodiles eat the snails in which the parasites are responsible to expend the part of their life cycle. Crocodiles are important components of the food web in an ecosystem. Eradication of any species from its ecosystem extremely modifies the population structure of other creatures. Crocodiles as top predators are known as elementary species; though they moreover contribute to the food chain as prey at the same time as they are still young. Crocodilian species can also have a useful anthropogenic role in the environment. In some areas, crocodiles are helpful to control the numbers of serious agricultural pests by consuming rodent and insect pests. Crocodiles are being farmed in captivity in all over the world these days for commercial purpose. Conservation of Marsh crocodile in Pakistan through sustainable use is seen as the strategy that could save the only existing species of order Crocodylia in the long run.