Prawns have good domestic and international markets. Prawns may be caught or cultured. Prawn culture is aquaculture. Prawn culture is carried on three districts in West Bengal such as North 24 Parganas, South 24 Parganas, and Purba Midnapore. Prawn culture in these districts plays a vital role in providing gainful employment in rural areas earning foreign exchange and improving the economy. But prawn culture has some bad effects on the environment. The externalities of prawn culture are reduction of cultivation work, threatening food security, ecological imbalance, diminishing fertility of the land, environmental degradation, salination of drinking water, ill health, skin diseases, social pollution, etc. These costs destroy the socio-economic balance of the coastal area. So these costs need to be accounted for in environmental Accounting. Primary data are used for this exploratory research. Some good management practices should be followed to make sustainable prawn farming reducing externalities.