Background  To understand immunological responses in chimpanzees vaccinated with live‐attenuated vaccine (oral polio vaccine; OPV), serum neutralizing antibodies against poliovirus types 1, 2, and 3 were investigated over time. Methods  The neutralizing antibody titers against poliovirus types 1, 2, and 3 were determined by microneutralization test using 100 ID50 of poliovirus types 1, 2, and 3 (Sabin strains). Results  Neutralizing antibodies against poliovirus types 1, 2, and 3 were detected in 85.7%, 71.4%, and 65% of the serum from 42 chimpanzees tested 9 years post‐vaccination. The neutralizing antibody titers in chimpanzees were similar to the documented levels in human studies as an indicator of vaccine efficacy. Conclusions  This study reveals persistence of neutralizing antibodies in chimpanzees for at least 9 years after vaccination with OPV. This first study in chimpanzees provides useful information for the evaluation of the success of vaccination with OPV in other captive apes.