Two male date palm cultivars, "Ghanami akhdar" and "Jarvis," were studied in order to determine the effects of gibberellic acid (GA3) and naphthalene acetic acid (NAA) on their pollen grain viability, germination, and pollen tube elongation., Different level of each GA3 (10, 50 and 100 mg L-1 ) and NAA (1, 2 and 3 mg L -1) were used. The viability and fertility of pollen grains were tested by applying same levels to the aqueous pollen suspension using in date palm pollination in the field. The result showed that GA3 at 100mg/L improved date palm pollen germination through accelerating germination rate and pollen tube growth which reflected on the speed of fertilization. Application of 100mg/L GA3 upon pollination, also, led to the best results in term pollen tube growth and fruit set at Khelal stage; this may refer to a relationship between the amount of GA3 in pollen grains and its role in fertilization, fruit growth and development. NAA at these (1, 2 and 3 mg L -1) concentrations can present an effective thinning method in "Medjool". On other hand, no significant differences between cultivars were observed in vitro, but "Ghanami akhdar" outperformed "Jarvis" in vivo. "Ghanami akhdar" can be considering as a recommendable pollinator for "Medjool".