The interference of Infectious bursal disease (IBD) virus and vaccine with the immune response of the grey brested guinea fowl (Numida meleagridis galeata palas) to Newcastle desease (ND) "LaSota" vaccine was studied using hemagglutination inhibition (HI) test for detection of ND virus antibody and agar gel precipitation test (AGPT) for the presence of IBD virus antibody. A statistically significant difference (p<0.05) in HI antibody response was noted between the group vaccinated with ND "LaSota" vaccine alone and those infected with IBD virus or vaccinated with IBD vaccine and later vaccinated with ND "LaSota". The Newcastle disease "LaSota" vaccinated group showed highest Geometric Mean Titre (GMT) of HI antibody response of 80 while the IBD virus infected and IBD vaccinated group gave 32 and 19 respectively. Expectedly the IBD infected or vaccinated groups seroconverted to the IBD infection or vaccination. It is concluded that IBD virus or vaccine interfered with the immune response of the guinea fowls to ND "LaSota" vaccine.