The use of nanotechnology as a fertilizer has been suggested in various researches as a tool for promoting progressive nutrients use efficiency, lessening nutrients losses through water irrigation and volatilization and enhancing crop yield stability. This experiment was carried out in the two growing winter seasons i.e., 2021/2022 and 2022/2023, aimed to Enhance the flowering and yield of faba bean (Vicai faba) by foliar application of algal Spirulina platensis and nanoparticles of silicon and boron to reduce flower drop, increase the number of flowers on the plant, and increase yields. A modified amount of Spirulina at a rate of 2.0 gL-1, silicon nanoparticles at a rate of 100 ppm L-1, and Boron nanoparticles at a rate of 100 ppm L-1 either individually or combined each other on two faba bean (Nubaria-1 and Sakha-3) Cultivars by using Strips-Block design in three replications. Results indicated that the foliar spraying separately or combined increased the N, P, K, Ca, total carbohydrate and chlorophyll contents in the leaves of Nubaria-1 and Sakha-3 compared to the control. All foliar treatments decreased the shredded flowers consequently increasing the setted pods, and increased the biological and seed yields compared to the control with nonsignificant difference between the two cultivars in two seasons. The results, indicate that spraying with Sp+Si, Sp+B, and Sp+Si+B gave highest values for a number of flowering, pod weight, seed, biological, and protein yields of the two faba bean varieties. The seed yield was positively correlated with all studied traits under all treatment combinations