Gamma radiation, various absorbed doses (0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5 krad) effects were evaluated on sunflower ( . L.) germination and growth characteristics. Sunflower healthy seeds were exposed to gamma radiation source Co at nuclear institute for food and agriculture and exposed seeds were grown under controlled laboratory conditions. In comparison to control, gamma radiation absorbed doses affected the measured response positively i.e., radical length, plumule length, number of roots, seedling fresh weight, seedling dry weight, germination percentage, time of germination and diameter of hypocotyl of sunflower enhanced up to 83.15%, 70.32%, 73.03%, 4.80%, 3.26%, 72.0%, − 18.88% and 12.58%, respectively. The time of germination, fresh weight and percent moisture contents enhanced insignificantly, however, the response was higher than control. All gamma radiation absorbed doses showed a stimulatory effect on sunflower germination and seedling growth characteristics. The low gamma radiation absorbed doses were found to be more effective versus higher doses for enhancing the germination and growth characteristics of sunflower. In view of positive effect of gamma radiation of sunflower germination and growth characteristics, it is concluded that this techniques could possibly be used for the enhancement of germination, growth and ultimately yield in sunflower in areas where germination is low due to unfavorable conditions.