Many of the wild grasses are important reservoirs of agronomically superior traits which can continue to help to improve the current cultivars of wheat, rice, barley, oat, maize and other cereals. An understanding of genomic and hence phylogenetic relationship helps in planning effective breeding programs designed to transfer desirable genes from alien species into otehrwise superior cultivars of crop plants. In the last few decades, cytogeneticist and plant breeders have successfully transferred several plant traits into cereal crops from their wild relatives through intergeneric and interspecific hybridization. Several biochemical and molecular techniques have been used to characterize the alien chromatin/genes introgressed into crop cultivars, thus helping the process of germplasm enhancement. This article evaluates the molecular aspects of wide hybrids and genome relationships between cereal crops and their wild relatives and suggests future lines of work on improvement of cereal crops by this technology