In this study, a combined Trivalent vaccine against ND, IB and M. gallisepticum was locally prepared and evaluated in comparison with other locally prepared Bivalent ND and IB and monovalent M. gallisepticum vaccines. The obtained results were promising for this locally prepared Trivalent vaccine and the immune response was outstanding starting at the 2nd week post vaccination and showed extended raising allover the experiment period. The immune response of chickens vaccinated with the Trivalent was shoot up post boostering at the 8th week post 1st vaccination. These results were confirmed and supported by the challenge tests using the virulent strains of the three pathogens. So it could be recommend that the production of this Trivalent ND, IB and M. gallisepticum will help in the control of the three diseases and their complications.