Abstract: A laboratory study was conducted to evaluate the effect of seed priming using different priming agents with different concentrations (KNO3, Polyethylene Glycol (PEG 6000), ascorbic acid, α-tocopherol, folic acid and seaweed extract) and hydropriming compared with unprimed seed on seed and seedling vigor of two sunflower (Helianthus annuus L.) cultivars i.e., Sakha 53 and Giza 102 during 2009 season. Also, field experiments were carried out to investigate the influence of the best concentration selected of each priming treatment from laboratory experiment on yield, its components and quality of the same two sunflower cultivars during 2009 and 2010 seasons. In most cases, seed priming treatments reduced the Mean Germination Time (MGT), increased Germination Percentage (GP), Germination Energy (GE) and Germination Index (GI) and improved Seedling Length (SL) and Seedling Dry Weight (SDW) in both cultivars under laboratory conditions. Data analysis in the field experiment observed that Sakha 53 significantly surpassed Giza 102 in yield, its components and seed oil percentage. While, Giza 102 surpassed Sakha 53 in seed protein content. The highest values of capitulum diameter, 100-seed weight and seed yield/ha were observed by the application of 75 mg L-1 ascorbic acid in both seasons. Also, the highest values of seed yield/plant and seed oil and protein% produced from seed primed with 15 mg L-1 folic acid in the second season. Sakha 53 was better than Giza 102 as an oil source because of its highest content of oleic acid and unsaturated fatty acids percentages. It may be concluded that seed priming agents can be used for improving the germination and seedling vigor of sunflower seeds. In addition, planting Sakha 53 cultivar and seed primed with 75 mg L-1 ascorbic acid or 15 mg L-1 folic acid can achieve high yield and oil quality of sunflower. So, seed priming can be used as a beneficial method to improve seed performance and plant traits of sunflower.