Complementally field experiment was conducted during 2007 season at Kafr-El- Hamam Agricultural Experiment Station of Agricultural Research Center, Sharkia Governorate, Egypt to screen thirty–three sunflower inbred lines had been selected  from stock breeding materials of Oil Crops Research Section in addition to two check cultivars i.e. Sakha 53 and Giza 102 under two water treatments; watering every 15 days (control experiment) and prevented irrigation after El-mohyah irrigation (drought experiment) using osmotic adjustment. Osmotic adjustment estimated as the differences in osmotic potential at full turgor between drought and control treatments.              There was no effect of osmotic adjustment on all studied traits in the irrigated control. Oil yield per feddan rather than seed yield per feddan, was the yield characters most affected by level of osmotic adjustment. Mean squares due to irrigation levels were highly significant for all studied traits. The differences among genotypes were highly significant for all studied traits. Significant genotype x irrigation levels interaction was detected for all studied traits. The highest values for yield potential were owned to Sakha 53 and G13. Highly significant positive correlations were detected between osmotic adjustment and yield characters. It was concluded that genotypes G 13 and cultivar Sakha 53 of high osmotic adjustment had a superiority in the direct use at drought affected soil and/or for breeding program to pursue further advancement in sunflower drought tolerance.