The cultivated olive in the west Mediterranean basin seems derived at least from two processes: (i) domestication from their wild relatives and (ii) introgression related to hybridization between introduced cultivars from east Mediterranean and local cultivars. To test this hypothesis, we analysed the genetic structure of 476 Mediterranean olive cultivars using 12 nuclear SSR loci and chloroplast DNA polymorphism. We confirmed the presence of the East and the West gene pools and we showed that the western gene pool has eastern maternal lineage. These results suggest that cultivated olive is a result of selection of olive seedling issued from crossing between introduced cultivars and local populations. This finding was supported by ethnobiological study conducted on current farming practices in principal traditional agro-ecosystems in the north of Morocco. Hence, olive diversification seems to be a dynamic process that mainly arose through sexual reproduction in traditional agroecosystems.