Two field experiments were conducted at El-Baramoon experimental farm of Horticultural Research Institute, Mansoura Governorate during 2006 and 2007 late summer seasons, on sweet pepper plants cv. California Wonder. The study aimed to investigate the effect of some antioxidants and nutrients in organic form to alleviate the adverse effects of high temperature stress and its related oxidative one; vitamin E-selenium (150 ppm vitamin E) – vitamin C (150 ppm) – zinc citrate (100 ppm Zn) – calcium citrate (2000 ppm Ca) were sprayed singly or in combinations. The obtained results showed that, all applied treatments ameliorated stress effects and significantly improved fruit yield (No. of fruits / plant, fruit average weight, fruit yield / plant and total fruit yield / fed.) and its physical (fruit length, fruit diameter and flesh thickness) and chemical quality(TSS %, vitamin C, total acidity % and dry matter %). The combination of zinc citrate + calcium citrate (100 ppm Zn + 2000 ppm Ca) or vitamin E-selenium + zinc citrate (150 ppm vitamin E + 100 ppm Zn) gave the highest significant results in both seasons, respectively