The main objective of nano-fertilizers applications in agriculture is to minimize mineral fertilizers losses and increase yields to support agricultural production. Thus, this investigation was conducted in Gemmayze Station, El-Gharbia Governorate, Egypt, during the two growing seasons of 2017 and 2018 to investigate the efficacy of zinc nano particles on yield, quality and as a remedial zinc nano-fertilizer for soya bean and wheat corps.  To confirm the size, shape, surface structure, crystalline composition, and analysis of elemental proportion, synthesized zinc nanoparticles have been characterized. ZnO nanoparticles were either applied foliar spray or soil addition at different concentrations (0, 5 and50 mg L^-1). In this experiment, three amounts of phosphorus were used (0, 50 and 100% of the prescribed dose). The obtained results showed that the foliar application of ZnO nanoparticles was effective for enhancing crop production compared to soil application one. In addition, foliar spray led to improve the quality of crop, and the highest increase of yield was noticed by using 50 ppm ZnO nanoparticles under maximum recommended dose of phosphorus fertilizer (100%P). This increase reached to 1.4- folds than control treatment under maximum P application (100%). However, the increment reached 1.9-folds than zero zinc with zero P application. ZnO nanoparticles improved crop yields quality in terms of protein, carbohydrate, crude lipid and N, P, K and Zn of soybean and wheat. The results showed slight decrease in nitrogen and potassium concentration in the soil with increasing ZnO nanoparticles concentration in both type's application (foliar spray and soil addition).