Water stress was imposed on four varieties of Indian mustard viz., PusaBahar, Varuna, Pusa Jai Kisan and PusaAgraniby withholding irrigation at 3 different stages of crop growth ., vegetative, reproductive and pod-filling stage. The maximum impact of water stress on total chlorophyll content was observed at pod filling stage. The total chlorophyll content decreased a maximum in cv. PusaAgrani and minimum in Pua Jai Kisan. Proline accumulation increased in all the test verities and maximum accumulation was observed at reproductive stage. Cultivar Varuna registered the maximum proline accumulation. Total chlorophyll and proline content can be considered as the desirable traits for screening the cultivars for drought prone environments.