This study was carried out through 2011, 2012 and 2013 seasons in a private farm at Cairo- Alexandria desert road on 9-years-old of "Manzanillo" and "Picual" olive cultivars. The trees were planted at 4 x 6 m apart on sandy loam soil under drip irrigation system. Nevirol (N-Phenyl-Phthalamic acid) applications at different concentrations at 0, 50, 100, 150 or 200 ppm were foliar sprayed at full blooming stage. Results showed that 50 ppm Nevirol was more effective in improving fruit set percentage (by about 28.0 %), retained fruits %, fruit yield (by about 14.2 %) over the control once. On the other hand, fruit characters; fruit weight, size, dimensions, shape, flesh weight, seed weight, fruit moisture and oil content were not affected by Nevirol treatments, hence 200 concentration were ppm significantly decreased fruit characters of the two studied olive cvs. However, histological studies showed that 50 ppm Nevirol enhanced fruit set by improving pollen tube growth through the style than the other higher concentrations of Nevirol or control.