This study was conducted to evaluate the physiological impact of seed priming on improving the salt tolerance of tomato cultivars H-2274 and Rio Grande. Tomato seeds were primed with 5 M NaCl solution at 20 degrees C for 3 days in a dark environment. The seeds of the control treatments were handled in a similar way, using tap water instead of NaCl solution. After the priming procedure, seeds were washed and sown in standard germination trays. From each treatment group, 21 homogeneous seedlings were transplanted into 10-L pots full of turf for subsequent salinity experiments. In order to avoid osmotic shock, the volume of the applied NaCl solutions (0 mM, 100 mM, and 200 mM NaCl) was increased from 30 mL/day to 50 mL/day after 5 days. As a major physiological parameter, the chlorophyll content was evaluated 3 times during the experimental phase. Furthermore, the mineral compositions (Na, K, Ca, and Mg) of the leaves as well as the content of soluble sugars (glucose, fructose, and sucrose) were evaluated at the end of the experiment. Consequently, it was found that seed priming with NaCl may provide a good alternative to reduce salinity-induced stress in tomato plants.