It is assumed that the cultivation of olive trees started in the East Mediterranean in the third millennia bce. Throughout history and until recently, successful olive clones were maintained vegetatively and were grafted either on seedlings or on spheroblasts removed from the base of the trunk. It therefore can be hypothesized that local old olive trees, older than 500 years might represent an ancient gene pool. Modern terminology categorizes local genotypes into four main variety groups. However, in traditional terminology these were further differentiated into 27 cultivars according to their phenotypic traits. This genetic diversity, along with the fact that olive trees have been cultivated in a wide range of environmental conditions, might also suggest that adaption to specific conditions played a major role in the selection of rootstocks and scions. We therefore consider it important to start aconservation program of this valuable genetic resource that can be used in future breeding programs.