Six parental flax genotypes i.e. three dual type G 8 (P1), S.997 (P2), S.954) (P3) and three fiber type (S. 888/22 (P4), S.103 (P5) and Bombay (P6) were crossed in all possible combinations excluding reciprocals for generating 15 F1,s then 15 F2,s in 2018/2019. For estimating combining ability and gene action for straw and seed yields and their components in flax,  six parents and their 15 F1,s and 15 F2,s progenies were evaluated in a randomized complete block design with three replications in 2018/2019, 2019/2020 at Giza Agric. Res. Station  Farm, Giza Governorate, Egypt. P2 (S. 997) and P5 (S. 103) exhibited significant positive GCA effects for straw yield, plant height and fiber percentage. Whereas, P1 (Giza 8) showed significant positive ĝi values for seed yield/plant and oil percentage. . Significant positive SCA effects were detected in  P1× P2, for straw yield/plant, P1× P6 for plant height and P1× P5 for both of technical stem length and fiber percentage which involved high × low general combiner parents. It could be concluded that the these breeding materials are suitable in breeding for increasing the above-mentioned characters. Significant positive correlation coefficients between GCA values and parental means  as well as between cross means and their SCA values were observed. Hence, selection of parents and their crosses in flax breeding program could be depended on their higher mean performance for studied traits.