Field mustard which accounts for 28% of total oilseed production in India emphasizes the need of developing improved stress tolerant varieties to meet future world food demand. Several abiotic stresses that influence hydrological balance, rate of photosynthesis, nutrient movement, etc. reduce plant development, thus ultimately causing yield loss. In Brassica campestris, multiple adaptation strategies such as antioxidant defense mechanisms, ion homeostasis regulation, and stress genes have been studied to thwart destructive effects. To counter abiotic stress, plants develop an antioxidant defense mechanism using metabolites like allantoin and phytohormones to increase their stress resistance. Critical stress responsive genes have been identified as contributing to plant stress resilience. For stress-resilient cultivars, it is necessary to explicate the physiological mechanisms determining how stress responses are determined. This chapter reviews responses of Brassica campestris to various abiotic stress conditions with emphasis on recent advances in knowledge of stress adaptation mechanisms and future views for sustaining such crops through biotechnological approaches.