Grapevine downy mildew caused by the Oomycete Plasmopara viticola is one of the most important diseases affecting Vitis spp. The current strategy of control relies on the use of chemical fungicides. An alternative to the use of fungicides is the use of downy mildew resistant varieties, which is cost-effective and environment friendly. However, all cultivated European grapevine varieties are susceptible to P. viticola and the resistance needs to be introduced from other Vitaceae though breeding programmes. Using segregating populations derived from different resistance sources we have identified several resistance genes. Identifying the cognate avirulence genes from P. viticola is a necessary step to understand the biology of the interaction as well as to choose the most efficient combination of resistance genes in a strategy of pyramiding.