The present study was conducted to investigate the immunoenhancing effects of Montanide™ ISA 71 VG adjuvant on profilin subunit antigen vaccination. Broiler chickens were immunized subcutaneously with a purified Eimeria acervulina recombinant profilin protein, either alone or mixed with ISA 71 VG, and host immune responses were evaluated. After secondary immunization, antigen-specific antibody and T-cell responses were higher in the group which received profilin plus ISA 71 VG compared with the other groups. Furthermore, body weight gains and fecal oocyst shedding were evaluated following oral challenge infection with live E. acervulina or Eimeria tenella oocysts. Vaccination with profilin plus ISA 71 VG reduced oocyst shedding compared with animals immunized with profilin alone. These results demonstrate that the recombinant profilin subunit vaccine, when given in combination with Montanide™ ISA 71 VG, augments protective immunity against E. acervulina and E. tenella.