Two field experiments were carried out in the Desert Research Center (D.R.C.), Agricultural Experiment Station at EL-Kharga Oasis, New Valley Governorate, Egypt, during the two summer growing seasons of 2010 and 2011. This study aimed to investigate the effect of potassium fertilizer rates (0, 36 and 72 kg K₂O per fad.) and boron foliar levels (0, 226, 452, and 678 ppm) on yield and its components of three maize cultivars i.e. Giza-10, Giza-321 and Giza-324. Results indicated that Giza-321 cultivar significantly surpassed Giza 10 and Giza-324 in all studied yield parameters. The use of boron fertilizer at the level of 452 ppm showed significant superiority for all studied yield components compared with the control (without boron foliar). Moreover, these parameters were significantly higher under using high level of potassium fertilizer (72 kg K₂O per fad.) compared with control treatment (without potassium fertilizer).