In the study, 20 hormonally bursectomized and 20 intact (control) eggs from native hibrit lines were used. Haematological examinations were performed in these birds at 1., 5., 10. and 15 th weeks of their ages It was not obtained any differences between the groups in respect ol erythrocyte, leucocyte and thrombocyte counts, ha-emoglobine and haemotocrit levels at any time period. Percentages of lymphocyte in the bursectomized group were significantly lower than in the control animals at 1 and 5 th weeks of their ages (P<0.05). In the same sampling times eosinophil percentages (7.80, 6.60 %, respectivety) in the bursektomized group were observed to be significantly higher than those in the control group (3.80, 4.20 %, respectively). On the other hand in the bursectomized group heterophil counts were determined relatively higher due to the decrease in lymphocyte counts as compared with the control group. The differences between the groups in respect of the percentages of lymphocyte, heterophil and eosinophil were disappared after 5 th week although eosinophil and heterophil counts were still higher in the bursectomized group. In conclusion, hormonal in ovo bursectomy like surgical bursectomy resulted in higher eosinophil count and both B and T lymphocytes are necessary to maintain eosinophil count in normal range.