Moringa oleifera is an important and promising tree, growing in many arid and semi-arid areas. Moringa plant is effective and suitable source of nutrition and medication. The present work was carried out to study the response of two barley genotypes to a foliar application of moringa leaf extract (MLE) as a growth enhancer at the vegetative stage. The obtained result showed enhanced antioxidants activities (superoxide dismutase, peroxidase & catalase) in leaves of the barley genotypes under MLE application compared to the control. Similar results were detected in the case of plant growth, leaf photosynthetic pigments, building material and some minerals contents in both tested barley genotypes. In contrasts, lower malonadialdehyde (MDA) content was obtained under MLE treatment in the studied barley genotypes. The application of MLE resulted in good growth stimulation. Better enhancement was detected in Giza124 than Giza129 barley genotypes. In conclusion, foliar treatment with MLE as a bio-growth enhancer improves the antioxidant capacity and plant secondary metabolites of barley leaves. Thus, Moringa oleifera leaf extract is recommended to be applied widely as a bio-organic fertilizer for various crops due to its good productivity, highly nutritive and antioxidant system and low cost.