A serological survey was carried out on 429 dogs belonging to the French military in France, French Guyana, Martinique, Senegal and the Ivory Coast. Serology against phase I and II antigens of Coxiella burnetii, the intracellular zoonotic bacterium was performed using indirect immunofluorescence techniques. Specific antibodies were found in dogs from France (9.8%), Senegal (11.6%), Ivory Coast (8.3%), French Guyana (5.2%) but not in those from Martinique. The seroprevalence among 77 dogs who had contact with sheep compared with 352 dogs who had had no contact, demonstrated a significantly higher seroprevalence in the former. Our results indicate that dogs, living close to sheep, may be infected by Coxiella burnetii and should be considered as possible sources of infection for humans.