ABSTRACT:We assessed West Nile virus (WNV) antibody prevalence in American Kestrels (Falco sparverius) in southern Quebec by sampling 152 birds during the 2003-05 breeding seasons. We analyzed the dependence of antibody prevalence on age group, year, and gender; a significant relationship was detected only between age (adults vs. nestlings) and antibody prevalence. Furthermore, reproductive success did not appear to be linked with the prevalence of anti-WNV antibodies in this population.