Fowl pox-vectored Mycoplasma gallisepticum vaccine (FPVMGV) is a recombinant fowl pox virus vaccine expressing protective Mycoplasma gallisepticum antigens which could facilitate the prevention of both fowl pox virus and M. gallisepticum infections. The objective of the present study was to determine the efficacy of fowl pox-vectored Mycoplasma gallisepticum vaccine as compared with live attenuated fowl pox, live mycoplasma gallisepticum and inactivated mycoplasma gallisepticum vaccines. The FPVMGV was proved to be safe based on clinical findings and gross pathological lesions of air sacs and peritoneum of the inoculated experimental chickens. FPVMGV was proved to induce higher protection (93%) than that induced by the conventional live (86%) and inactivated MG (80%) vaccines, in addition the vaccine induced protection against the challenge with fowl pox virus (92%) less than that in case of live attenuated fowl pox vaccine. On the other hand, the available commercial ELISA kit for detection of MG antibodies failed to detect any seroconversion in chicken vaccinated with the Fowl pox-vectored Mycoplasma gallisepticum vaccine contrally to the results obtained in the other two conventional MG vaccines. In conclusion, the fowl pox-vectored Mycoplasma gallisepticum vaccine could be a good option for use in chicken to prevent FPV and M. gallisepticum infections.