A field experiment was conducted at the Experimental Farm of Sakha Research Station, Kafr El-Sheikh Governorate, Agricultural Research Center, Egypt during 2017/2018 and 2018/2019 seasons to study the effect of mineral, bio-nitrogen fertilization and their combinations i.e. 45 kg N/fed, Nitroben and Nitrobein plus 30 kg N/fed on the straw and seed yields as well as their components of three flax varieties i.e. Sakha 5, Sakha 6 and Giza 11. A split plot design with four replicates was used. Results showed that varieties, fertilization treatments and their interaction, significantly affected straw and seed yields as well as their components in both seasons. Giza 11 variety was superior in straw and seed yields as well as their components over other varieties. Dual application of mineral N with N bio-fertilizer (Nitrobein plus 30 kg N/fed) produced the highest values of straw and seed yields as well as their components. The highest values of all traits were obtained from planting Giza 11 variety fertilized with dual application of mineral N and N bio-fertilizer (Nitrobein plus 30 kg N/fed). Hence, dual application of 30 kg N/fed with N bio-fertilizers could be recommended for improving flax varieties production especially Giza 11 variety under Kafr El-Sheikh Governorate conditions, Egypt.