Phytoestrogens represent a family of plant compounds such as isoflavones, flavones and lignans. A variety of these plant compounds have been identified in various human body fluids. A wide range of commonly consumed foods contains appreciable amounts of these different phytoestrogens, viz. soy products are particularly good sources of isoflavones and lignans. Accumulating evidences from molecular and cellular biology experiments, animal studies, and to a limited extent, human clinical trials suggests that phytoestrogens may potentially confer health benefits related to various cancers and diseases such as cardiovascular disorder. The evidences reviewed here represent the beneficial effects of most potential and promising isoflavone, Genistein in various types of cancers.