This study was carried out to determine the effect of primig treatments (2% KNO3, 1% NaCl, 500 ppm GA3) on seedling emergence and seedling growth of two tomato rootstock seeds for two experimental runs. Although all treatments were superior to control, KNO3 was found the best treatment. Treatments were not significantly effective on final emergence but reduced significantly mean emergence time, T50 time to 50% emergence, T1.5 time to reach 1.5 mm hypocotyl thickness and increased seedling size (fresh and dry weight). Although all treated ones had remarkably effective but the greatest reduction in coefficient of variation (CV) in KNO3 treated seeds indicated that treatment also reduced plant to plant variation among the seedlings. Results indicated that priming is rather effective through reducing germination time than subsequent relative growth rate and a valuable tool to improve seedling quality in turn obtaining thicker and well-developed seedlings in rootstock tomato seedling production. © 2006 Asian Network for Scientific Information.