The present study was carried out in both laboratory and the experimental field of Sakha Agricultural Research Station, Kafr El-Sheikh Governorate during two successive seasons (2008 and 2009) to evaluate the role of certain mortality factors in reducing the field populations of Coccinella undecimpunctata L. on different crops. The coccinellid predator was recorded to be parasitized by the two hymenopterous parasitoids, Tetrastichus coccinellae Kurdjumove (Eulophidae), and to be infected with bacteria Bacillus spp. and two species of fungi (Penicillium sp. and Fusarium sp.). Overall crops during 2008, the highest percentage of the total population mortality was caused by parasitoids (49.88%) and the lowest by unknown mortality (2.24%), as well as the highest contribution in the total mortality was recorded by parasitoids and the lowest by unknown mortality. The mortality was caused by fungi came in the second rank (6.73%) and contributed to (10.71%) of total mortality. Mortality was caused by bacteria contributed with low percentage in the total mortality (6.35%). During 2009, on different crops, the highest percentage of the total population mortality was caused by parasitoids (48.27%) and the lowest by bacteria mortality (4.70%), as well as the highest contribution in the total mortality was recorded by parasitoids and the lowest by bacteria mortality. The mortality was caused by unknown came in the second rank (8.91%) and contributed to (12.90%) of total mortality. Mortality was caused by fungi came in the third rank and contributed with 10.39% in the total mortality.