The population dynamics of Mediterranean fruit fly (MFF), Ceratitis capitate (Wied.) and Peach fruit fly (PFF), Bactrocera zonate (Saund.) were studied in apricot orchards at Sinuris and Ibshaway districts, Fayoum Governorate, Egypt during the two successive seasons 2003 and 2004. In the mean time, rate of infestation in apricot fruits with MFF & PFF together and separately were estimated. During the two successive seasons, MFF population was low compared with PFF population. Captured per trap per day "CM" for MFF ranged between 0.1-8.4 flies with mean of 2.4 flies, and between 0.0-1.05 flies with mean of 0.42 fly, during the two successive seasons, respectively. "CM" of PFF ranged between 12.2-133 9 flies with mean of 54.2 flies and between 7.00-23.57 flies with mean of 13.16 flies during the two successive seasons, respectively. Total percentages of infestation with MFF & PFF together at apricot locations ranged between 6.99 % -22.17 % with mean of 15.00 % and between 8.40 % - 11.67 ⁰/0 with mean of 9.86 %, during the two successive seasons, respectively. Percentages of infestation with MFF separately ranged between 0.18 % - 5.85 %, with mean of 2.24 % and between 0.46 % - 0.76 % with mean of 0.64 %, during the two successive seasons, respectively. Percentages of infestation with PFF separately ranged between 6.81 % -19.93 % with mean of 12.76 %, and between 7.64 % -11.13 % with mean of 9.22 % during the two successive seasons, respectively.