The current study was conducted to assess the possibility of using two bio-agents (BAs), Trichoderma harzianum T39 (Trichodex) and Bacillus subtilis (MBI 600) tested at 1, 3 and 5% concentration to control damping-off disease and also their ability to promote yield of wheat lines under field conditions. Seed inoculation with two BAs protected wheat seedlings and highly promoted seed germination. Also, inoculation with BAs significantly affected number of spikes/plant, biological yield/plant and grain yield/plant and there were statistically significant differences between bread wheat lines under field conditions. Moreover, the treatments at 5% of T. harzianum and B. subtilis were the best treatments to increase grain yield. Four lines, L11, L12, L27 and L38 were found to be more responsive to BAs treatments under field conditions.