The cytological analysis of the tested olive cultivars indicated that the haploid number of chromosomes in each of Teffahi, Chemlali, Wardan, Picholine, Pocoma and Hamed was 23 chromosomes. In addition, each of Pocoma and Chemlali olive cultivars had more regular chromosomal behaviour during the different stages of meiotic division than the other tested cultivars. Moreover, their pollen grains were highly viable by stainability and germination tests. On the other hand, Teffahi and Hamed olive cultivars exhibited the lowest percentages of bivalent chromosomes and pollen grain viability. Nine pollination trials were conducted during 1998 and 1999 seasons which included the following treatments: open-pollination, bagging only, hand self pollination and bagging, emasculation and bagging, and cross-pollination using pollen grains of Chemlali, Wardan, Picholine, Pocoma and Hamed olive cultivars. The obtained data indicated that Pocoma olive cultivar can be used successfully in olive breeding programs due to its regularity of chromosomal behaviour during the different stages of meiotic division. In addition, cross-pollination is very important for improving fruit set, yield and improve fruit properties of Teffahi olive cv.