In Pakistan the poultry sector is an important and vibrant segment of agriculture in Pakistan with a significant contribution to the national GDP (1.3%). Mycoplasma gallisepticum (MG) causes avian mycoplasmosis and is only controlled through mass vaccination. Antibody response of birds to inactivated MG vaccine is poor. On 7th day of age (broilers: n=40) each bird of group A, B, C and D (n=8) was vaccinated (subcutaneous: 0.3ml) with G-MG, O-MG, G-MG+NDV (New castle Disease Virus) and O-MG vaccines, respectively. Serum samples were collected on 21, 28 and 35 days post vaccination for anti-MG-ELISA antibody titer. Cumulative mean anti-MG-ELISA antibody titer of birds to G-MG, O-MG, G-MG+NDV, O-MG+NDV and control was 80.30, 137.49, 91.59, 169.76 and 0.15 units respectively on 35 days post-vaccination. It is concluded that NDV has insignificant immunomodulatory effect on antibody response of birds to the MG vaccine.