Monovalent inactivated oil vaccines against Newcastle disease (ND), infectious bursal disease (IBD) and egg drop syndrome (EDS) in addition to a trivalent one were prepared and subjected to the quality control test. Each vaccine was inoculated in one of four chicken groups while a fifth chicken group was kept as non-vaccinated control. The humoral immunity was weekly detected and evaluated up to 24 weeks post vaccination in all groups. The results of haemagglutination inhibition (HI) test and serum neutralization test (SNT) revealed that all the used vaccines induced good levels of humoral immunity. Comparing results and monovalent and trivalent use of vaccine indicated that there was no interference between the used viruses in chicken immune response to each virus. So, we recommended use of trivalent vaccine to save time, cost and effort of vaccination as well as avoid repeated vaccination as a stress factor.