A total number of 140 Egyptian breed donkeys were used in this study. Animals are classified into two groups according to the sex. Each group was further subdivided into four subgroups according to their ages. All animals were proved to be health by clinical and laboratory examinations. Two blood samples were collected from each donkey, one with anticoagulant and the other without anticoagulant for obtaining clear non-haemolysed serum. Various tests were conducted to measure the values of some blood contents. It was clear that total RBCs count, hemoglobin content and packed cells volume showed marked decrease with the increase of age. Significant difference in RBCs count between some groups and highly significant difference in Hb and PCV contents between another groups. Gradual elevation in the values of total leucocytes count from one month up to 10 years old was observed. Marked decrease in total WBCs count was reported in animals of both sexes on 10-20 years old. This denotes that Significant and highly significant differences appear in total WBCs count between animal groups. The biochemical parameters revealed highly significant difference in the total protein and albumin in some groups of male animals. Non significant fluctuation was observed in blood serum calcium, phosphorus and magnesium regarding the age and sex factors. In conclusion, it was clear that both age and sex factors has a marked influence on some blood contents in Egyptian donkeys.