The present investigation to evaluate the impact of melatonin on physiological, biochemical characters and yield potential 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 and 60 DAP of the crop growth. Control (salt stress + no melatonin) and absolute control (no stress and melatonin) also maintained for comparison purpose. The salt stress of 120 mM NaCl was imposed from day one to120 days. Observations done on 45, 75 and 135 days after planting revealed that foliar spray of 100 ppm melatonin at 30 days after planting recorded percent increase of 33.56 in photosynthetic rate, 37.28 in stomatal conductance, 13.60 in transpiration rate and sett treatment plus foliar spray at 30 and 60 days after planting showed maximum osmotic adjustment, osmotic potential, proline (16.54 %) and soluble protein content (10.32 %). The melatonin treated plants are efficient in producing higher yield than untreated one under salt stress.