To investigate seasonal variation effects on oil contents and fatty acid pro file of some commonly grown sunflower hybrids, field experiments were conducted at the University of Arid Agriculture, Rawalpindi, Pakistan, during spring and autumn 2000. Five sunflower hybrids were sown in a randomized complete block design replicated thrice. Spring crop was planted in February and harvested in June, while autumn crop was planted in August and harvested in November. Results showed reduction of oil contents and oleic acid in autumn crop as compared with those of spring crop. However, palmatic and linoleic acid percentages increased more in autumn than in spring crop. It is concluded from this study that spring crop accumulated higher oil contents than of autumn crop with higher percentage of oleic acid. However, autumn crop produced seeds having higher percentage of linoleic acid.