Between 1990 and 1992, 91 necropsies of small ruminants affected with pulmonary illness led to the isolation of the following strains of Mycoplasma (M.): M. mycoides subsp. mycoides LC, M. ovipneumoniae, M. agalactiae, M. sp. type D2 and M. arginini. Eleven Pasteurella multocida strains (serotypes A1, A3, A5, A7 and D2) and 11 Pasteurella haemolytica strains (serotypes 1, 2, 3, 6, 7, 8 and 9) were isolated. Corynebacterium pseudotuberculosis, Actinomyces pyogenes, Staphylococcus sp., Streptococcus sp., Bacillus sp. and Mycobacterium sp. were also isolated. Thirty-two antibiograms were performed on Pasteurella, Corynebacterium pseudotuberculosis and Actinomyces pyogenes strains. Eighty eight p. cent were sensitive to penicillin G and oxytetracycline, and 84% to chloramphenicol; 50% were not sensitive to spiramycin and 47% to streptomycin. One Capripoxvirus strain was isolated on sheep. Pest of small ruminants (PPR) virus was detected by immunocapture ELISA test performed on some lung samples. Two serological surveys, one for contagious caprine pleuropneumonia (898 goats), between 1991 and 1993, and one for PPR (902 sheep and goats) in 1993, were conducted in the North and Far North provinces. No antibody against contagious caprine pleuropneumonia was detected. Among the animals in the sample, PPR prevalence was 64 +/- 7% in the Far North province and 14 +/- 3% in the North province. Concerning control measures, a vaccination campaign against small ruminant pasteurellosis appears to be hardly feasible because of the antigenic diversity of the isolated Pasteurella strains. PPR is endemic especially in the Far North province. The efficiency of a vaccination campaign against PPR must be estimated with a field survey.