White-tailed deer (n = 14 treated, n = 7 control) were examined postmortem to identify any possible pathophysiology resulting from PZP immunocontraception vaccination. Deer were treated twice in 1997; given a booster in 1998, with six being revaccinated in September 2000. Granulomas were found at injection sites of most deer, even 2 years post-treatment. Eosinophilic oophoritis occurred in 6 of 8 (75%) deer vaccinated in 1998, and 3 of 6 (50%) revaccinated in 2000. The 2000 revaccinates without oophoritis, had significantly fewer normal secondary follicles than control females (P = 0.03), and deer in the1998 treatment group (P = 0.04). PZP immunocontraceptive vaccine elicited ovarian pathologies in deer similar to those observed in other species. ?? 2007 Elsevier Ltd. All rights reserved.