Background and Objective: Sunflower is one of the most important oilseed crops in the world due to the high oil contents in its seeds.However, its production is less as compared to potential use due to weed competition as one of the most factors affecting production. This study aimed to raise seed production and consequently oil production through overcoming weed problems using natural extract of Moringa oleifera. Materials and Methods: Sunflower plants and associated Econocloa colonum grassy weed in pot experiment were sprayed with Root, leaf and seeds water extracts of Moringa oleifera at the two concentrations (5 and 10%). Results: The results indicated a significant reduction in Econocloa colonum growth by all types of extracts as compared to the control. The higher concentration of leaf extract induced Maximum inhibition. In contrast, the reduction in weed growth was accompanied by an increase in sunflower growth and yield which was attained more increase by a higher concentration of leaf extract (10%). The results indicated that total polyphenol contents in the leaf extract were more than double their correspondence in both root and seed extract. Flavonoids were found in leaf extract only. The total reducing sugar in both leaf and seed extract was more than that in the root extract. The antioxidant activity in leaf extract was more than double of their correspondence in seed and root extract. Conclusion: Results are promising for controlling weeds as well as growth enhancement of the target plants especially by leaf extract of Moringa oleifera.