Effect of different concentrations of Naphthalene Acetic Acid (NAA) on Barhee and Shahl date palm cultivars was studied on the bunch weight and both physical and chemical properties during two successive seasons 2005 and 2006. NAA ( 0, 50, 100, 150 and 200 ppm ) applications were sprayed on fruits of Barhee and Shahl cvs. 10 weeks after fruit set at depressed period. Results showed that NAA treatments significantly increased bunch weight, improved physical properties (fruit weight, height, diameter, and size and flesh weight percentage) and also increased the moisture percent of the fruit flesh of both Barhee and Shahl cvs. compared with untreated bunches. However, TSS, total and reducing sugars were decreased significantly by NAA treatments in fruit juice compared with the control in both seasons. Seed weight per fruit, acidity percentage and nonreducing sugars of both cultivars were not affected significantly by NAA treatments in both seasons. Results of this work suggest that 150- ppm NAA application could be used to increase the yield and improve fruit quality of Barhee and Shahl date palm cultivars