Acclimation activates an array physiological mechanisms and induce salt tolerance. Salt pre-treatment triggered ion exchangers located on plasmalema. Na+ sequestration primary in root tissues with little K+ leakage. Acclimation with 15 mM NaCl solution improved plant vigor under saline environment. Soil salinity is hampering the final output of crops by disturbing a set of physiological processes. The current study assessed; how did salt acclimation improve the salinity tolerance in field pea. Firstly, the 2-day old seedlings of pea (P. sativum) were grown in 105:15:117 ppm NPK solution for five days. Initially, two groups of seedlings were selected: acclimated (seedlings were exposed to 15 and 25 mM NaCl solution along with NPK solution for one week) and not acclimated. Further, the seedlings from both groups were grown in 4-kg plastic pots against moderate and severe salinity i.e. salinity levels of 6 and 9 dS m−1 for moderate and severe salt stress, respectively. Part of plants originated from the not acclimated group was kept in pots without salt stress as referent control. Different physiological kinetics were studied from control, acclimated and non-acclimated plants. Results show no detrimental effects of the salt acclimation on plant growth. Therefore, 15 mM NaCl acclimation and control treatments produced the plants with similar above-ground biomass. Further, acclimation triggered the accumulation of Na+ ions and prevention of K+ ions leakage primary from the root tissues, leading to higher photosynthetic rate (Pn), stomatal conductance (Gs) and chlorophyll contents. Subsequently, the acclimated plants either by 15 mM or 25 mM mediated relatively higher K+ ions in roots along with low sequestration of Na+ ions under moderate and severe salinity, suggesting that short-term exposure to salinity activates an array of physiological kinetics which enabling the plants to withstand severe salinity conditions. In conclusion, Acclimation with 15 mM NaCl solution was most effective to stimulate K+ sequestration in both leaves and roots, leading to i) higher photosynthetic rate and stomatal conductance, ii) more Chl a and total chlorophyll scores, and iii) high relative water contents and more dry biomass accumulation. [ABSTRACT FROM AUTHOR]