In this study, specific-pathogen free chickens as embryos at the 18^th day of embryonation were vaccinated with infectious bursal disease (IBD) vaccine viruses of low and of moderate virulence either alone or in combination with Nigella sativa oil. The vaccine of low virulence did not adversely affect hatchability of chicks or survival of hatched chicks and developed antibody against IBDV. On the other hand, the vaccine virus of moderate virulence was found to be not suitable for use in SPF-embryos (that free from maternal antibodies) as it caused extensive bursal damage in chickens of embryo vaccinated group. The IBD vaccines, especially of low virulence nature, could be combined with Nigella sativa oil and safely used as embryo-vaccination vaccine.