THE EFFECT of rates and methods of N application on growth …… and fruit yield, as well as the mineral content of Manzanillo olive trees, was investigated during two successive seasons 2008/2009 and 2009/2010. This study was carried out at Siwa Oasis in the Western Desert of Egypt between longitude 25°33′ and 35°81′ E and latitudes 29°10′ and 37°82′ N. Nitrogen fertilizer rates and application methods included of; 1) average recommended doses of soil application of 800g N/tree, 2) foliar 1% urea alone, 3) foliar 1% urea + 100% of soil N dose, 4) foliar 1% urea + 75% of soil N, 5) foliar 1% urea + 50% of soil N, 6) foliar 3% urea alone, 7) foliar 3% urea + 100% of soil N dose, 8) foliar 3% urea + 75% of soil N, and 9) foliar 3% urea + 50% of soil N, beside control treatment (without N). The obtained results showed a significant positive response of olive trees to all N fertilizer rates and methods as was reflected in growth parameters, fruit and oil yields as well as the mineral content of plant and soil compared to the control treatment. The combined applied of N soil of 100% N dose + foliar 1% urea significantly achieve the best growth parameters, fruit oil content with the highest economic fruit yield. It is worthy of mentioning that this treatment was also accompanied by increased mineral content of soil and plant. Noteworthy is that the sprayed urea of 3% + 100% soil dose gave an increased vegetative growth of trees at the expense of fruiting and oil content. Therefore, it could be recommended to use integrated of 800g N/tree as soil application with urea foliar spray of 1% for Manzanillo olive trees under conditions of Siwa Oasis and trees planted under the same conditions.