Immunization of mice with recombinant Mycobacterium bovis Bacillus Calmette-Guerin (rBCG) which over-produces a putative protective antigen candidate, the A component of antigen 85 complex (Ag85A), reduced the multiplication of Mycobacterium leprae in the foot pads of mice. The inhibition by this rBCG (rBCG/85A) was more evident than that with parental BCG. Repeated rBCG/85A immunization significantly could reduce M. leplae multiplication in mice. This is first report of rBCG to control mycobacterial infection in animal model. Therefore, rBCG technique may be useful for the development of a more effective mycobacteria vaccine.