Thirty-one grape cultivars from France and Northwestern Italy, presumed to be synonymous, were analyzed using RAPD (Random Amplified Polymorphic DNA) and SSR (Simple Sequence Repeats or microsatellite) markers to verify 25 synonym hypotheses. RAPD analyses were performed with 8 selected decamer primers and the profiles of 7 microsatellite loci were used in order to confirm RAPD results, if required. Sixteen synonymies were confirmed, including the French cv. Verdesse with the Italian cv. Bian ver, the French cv. Persan with the Italian cv. Biquet, the French cv. Chatus with the Italian cv. Neiret, the French cv. Gouais blanc with the Italian cvs Preveiral and Liseiret. Most of the investigated cultivars belong to the Vitis vinifera germplasm of both sides of the Western Alps and the occurrence of synonyms indicates the existence of a common pool of grapes grown under different names in this part of Europe.