Nuclear and chloroplast microsatellite loci were used to genotype Moroccan grapevine accessions (Vitis vinifera L.) from germplasm collections and from plants cultivated in farm fields or found under wild conditions. The genetic diversity of the global Moroccan sample was equivalent to what has been described for cultivated grapevines from other regions around the Mediterranean basin. The predominant chlorotypes among the analyzed samples were A and C, which are detected at higher frequencies in western and eastern regions of the V. vinifera range. Comparison of Moroccan accession genotypes with published genotypes for other grape-vine cultivars shows the existence of multiple synonyms, especially between cultivars grown in Morocco and Spain, as expected given the long history of interaction in the region. Analysis of genetic relationships among Moroccan samples distinguished groups of cultivated and wild samples. The wild samples had chlorotype A, which could represent remnants of natural populations of V. vinifera ssp. sylvestris (Gmelin) Hegi, or chloro-type C, which could represent cultivar derivatives or ancient cultivars generated by spontaneous hybridization among cultivated grapevines. Together the results point out the diverse genetic origin of cultivated and wild samples of grapevine in Morocco and emphasize the need to further collect and characterize its cultivated and wild grapevine germplasm. © 2010 by the American Society for Enology and Viticulture. All rights reserved.