An excessive dose of nitrogenous fertilizers more than its recommended doses and its improper application time lead to it's leaching to groundwater. Agricultural Nitrogen Model (ANIMO), a complex mechanistic model was tested on field scale to determine nitrate leaching in soil - aquifer system. This tested model along with water hydrology model SWAP were then integrated with ARC – GIS version 8.3 to determine nitrate pollution in groundwater on regional scale. Based on this integrated approach, future forecasting maps of nitrate pollution in groundwater of the study area were made for dominant wheat – rice cropping system.