Twelve grapevine cultivars from northern Portugal were characterized with RAPD and microsatellites. Nine primers were used in the RAPD analysis; 8 of the varieties showed monotypic patterns. With the 6 microsatellite loci a total of 38 alleles was obtained. Relationships among the studied varieties were observed. Both types of molecular markers have proved useful for identification. Existence of synonymies is discussed. K e y w o r d s : grapevine, identification, molecular markers, STMS, synonymies.