This study was conducted to evaluate the protective effect of Brucella melitensis Rev.1 and the use of BCG vaccine as immunostimulant by subcutaneous injection in Guinea pigs. Lab. animals were divided into 8 groups: Combined Rev.1 and BCG vaccines injected in the1st group & both vaccines were injected simultaneously in the 2nd group. Three groups sensitized with BCG vaccine then injected with Rev.1 vaccine one week, two week & three weeks intervals respectively. Other two groups were injected with BCG and Rev.1 vaccine individually. The last one was unvaccinated control. All injected animals showed resistance to infection with 16 M strain (90 %, 80 %, 80, 60 %, 70 %, 0 % and 70 % respectively).Thus animals vaccinated with bivalent Rev.1 and BCG vaccines (in one shot) showed the best protective level to infection