The blood picture of Habbard chickens was studied before and after vaccination with fowl pox vaccine. Total erythrocytes and leucocytes counts (in mm3 blood), differential leucoytic count (in %), haemoglobin content (in Gr%) were calculated in the whole blood. In addition total serum protein content was calculated in the blood serum. The obtained results indicated a great variation between vaccinated and nonvaccinated birds. The serum samples were tested for serum neutralizing antibody level and showed that the acquired immunity reached to its highest level within the second week post vaccination and persisted to the 6th week.