Molecular genetic linkage maps have and continue to be a major tool in genetics, genomics and breeding in plant and animal species. Linkage maps provide opportunities to analyze the complex genetics of quantitatively inherited traits through the localization of quantitative trait loci (QTL), identifi cation and positional cloning of genes, development of genome-wide physical maps using anchor markers. They can also serve as a repository of markers useful in marker-assisted selection. Since the publication of the fi rst genetic maps of Prunus, nearly twenty years ago, to those currently constructed, a signifi cant change has occurred increasing their accuracy. They are based on the analyses of larger segregating progenies and include more and more markers which are more informative, some of them corresponding to genes.