Type III secretion system plays an important role in pathogenesis of Pseudomonas (P.) aeruginosa. PcrV protein is a structural component of this system. Following the expression and purification of recombinant PcrV (r-PcrV), three shots of immunization were performed. Specific total and isotype (IgG1, IgG2a, IgG2b and total IgM) antibodies were measured after each shot. In addition, four weeks after the last immunization, immunized and nonimmunized groups of mice were burned and challenged with P. aeruginosa PAO1. To study the efficacy of the immunization, survival rate and bacterial quantity were evaluated in the skin, liver and spleen. All immunized mice were able to produce protective antibodies against P.aeruginosa PAO1. Anti-r-PcrV antibodies effectively enhanced (65%) survival rate of the immunized group in contrast to control group against challenge strain. Isotype antibody analysis revealed that the IgG1 was produced more than IgG2a in the immunized group. This phenomenon indicated, although both humoral and cellular immune systems were activated, of which the humoral immunity was the dominant immune response against P.aeruginosa.