Abstract: Background and Objective: The shoot succulent halophyte Sesuvium portulacastrum was previously shown to take up sodium (Na+) from the soil and accumulate it within its shoot tissues and was therefore chosen as a good plant for the phytodesalination of saline-sodic soils. The present investigation aimed to evaluate the ability of this halophyte to take up sodium and potassium (K+) from a saline medium and to check therefore its possible use in the phytodesalination of saline waters such as reject brines. Materials and Methods: Plants were hydroponically grown for one month in the presence of 200 mM NaCl, KCl or Na2SO4. At the harvest, leaves, stems and roots were weighed fresh and oven-dried then analyzed for K+ and Na+ contents. A One-Way-ANOVA test was used for data analysis. Results: Sesuvium portulacastrum showed a high tolerance to the three salts in terms of biomass production and water content. Plants accumulated high Na+ and K+ quantities, Na+ being more accumulated. Conclusion: The accumulated K+ quantities allow this halophyte to be used in the phytodesalination of saline waters such as reject brines.