The occurence of Haemophilus sp. and other potential pathogens: Streptococcus pneumoniae, Streptococcus pyogenes and Neisseria meningitidis has been investigated in 79 children from rhino and oropharyngeal material. H. parainfluenzae is only isolated from the oropharynx. H. influenzae and S. pneumoniae may be isolated from the rhinopharynx but are associated to signs of infection in the upper respiratory tract. The capsule of H. Influenzae represents a colonization factor of the rhinopharynx from an oropharyngeal carriage. 6.1% of H. influenzae and 28% of H. parainfluenzae isolates were found resistant to penicillin by production of betalactamase.