Abstract: Oxidative stress and red cell damage underline most pathological consequences. Isoflavones are group of compounds derived from soya beans. There is confusion in the literature regarding the antioxidant property of isoflavones. Hence, the present study was conducted to evaluate the antioxidant property of soy isoflavones and its protective role on red cells against free radicals and plasma protein degradation. Isoflavones were extracted from soya bean and free radical scavenging capacity was assessed by DPPH assay. It was found that the free radical scavenging capacity of isoflavones was 6.23 ± 1.04 µM/L equivalents of Gallic acid.