Cassava (Manihot esculenta Crantz) is considered as an important staple crop among the tropics and subtropics region and is the third largest source of carbohydrates. The varying climatic conditions like heat stress and drought causes depletion of ground water and increase the concentration of salt in irrigation water is getting increased. It is sensitive to moderate concentration of salt, particularly at early stages of development. During irrigation salt deposition takes place in the soil and causes drying of leaves, shedding of leaves, reduced tuber yield and quality. It was efficient that the use of melatonin, an anti-stress compound plays an important role in plant stress defence mechanism mainly related to drought and salt stress. The present investigation aimed at studying the impact of melatonin on physiological characters in response to yield potential and in improving salt tolerance of cassava under salt stress condition. The present study was carried out in cassava variety Sree Athulya with nine treatments under 120mM NaCl salt stress condition. Different treatments viz., sett treatment and foliar application of 100 ppm melatonin was done at 30 DAP and 60 DAP of the crop growth. Control (salt stress + no melatonin) and absolute control (no stress and no melatonin) also maintained for comparison purpose. The salt stress of 120 mM NaCl was imposed from day one to120 days. The results showed that, under salt stress condition among the treatments, sett treatment of melatonin 100 ppm plus foliar application at 30 DAP and 60 DAP followed by foliar spray of melatonin only at 30 DAP maximum photosynthetic rate, stomatal conductance and transpiration rate along with osmotic adjustment. The melatonin treated plants are physiologically efficient and provides higher yield than untreated one under salt stress condition.