Objective assessment of irrigation water requirement is crucial for optimal allocation and management of water in irrigated agriculture. Conventional estimation of field irrigation requirement involves computation of crop water requirement to meet the evapotranspiration requirement of the crop at the field level and canal level quantities are estimated considering the losses in conveyance, distribution and application. The in-season rainfall and its intra-seasonal variations are not considered. A study was carried out in Kurnool Cuddapah Command (KCC) area to estimate field level irrigation water requirement from soil water stress coefficient (Ks) derived from water balance components estimated from a process based hydrological model. The hydrological model (Variable Infiltration Capacity Model: VIC-3L) enabled simulation of soil moisture status along the soil column under prevailing rainfall conditions. This helped in identifying intermittent wet and dry periods requiring irrigation intervention. The irrigation water requirement is estimated by adjusting/adding requisite soil water through modification of crop coefficient proportional to the water stress coefficient (Ks) which is a function of root zone depletion of water. The field level irrigation water requirement at 8 day interval has been estimated for each of the Rabi seasons spanning over a decade of 2003–2013 for KCC area. The irrigation requirement varied between 135 and 165 mm. Validation of estimated irrigation requirement is attempted through correlating gap in supply and demand with the trends in crop production during the study years. The attempted methodology provides opportunities to estimate realistic irrigation requirement and future trends under projected climate change scenarios.