Five species of lung nematodes (Metastrongylus asymmetricus, M. confusus, M. elongatus, M. pudendotectus, M. salmi) and two species of stomach nematodes (Ascarops strongylina, Physocephalus sexalatus) were found in the wild boars (Sus scrofa) in France. Prevalence of lung nematodes was 92% (no significant difference between closed reserve and open areas could be demonstrated) and 97% for stomach nematodes. In both cases, intensity of infection was significantly greater in young wild boars (age < 1 yr) than in the older animals. The importance of intermediate hosts in the transmission of these infections is emphasized by the increased prevalences and intensities in certain high risk areas and during certain seasons.