Cultures of aerobic and anaerobic bacteria were obtained from the inferior nasal meatus of 25 children with purulent nasopharyngitis and from 25 controls. Microorganisms were isolated from all specimens. A total of 98 isolates (3.9 per patient), 45 aerobes (1.8 per patient) and 53 anaerobes (2.1 per patient), were isolated in patients with purulent nasopharyngitis. Seventy-three isolates (2.9 per patient), 47 aerobes (1.9 per patient) and 26 anaerobes (1.0 per patient) were found in the controls. The organisms recovered in statistically significantly higher numbers in patients with nasopharyngitis were Streptococcus pneumoniae, Haemophilus sp., Peptostreptococcus spp., Fusobacterium spp., and Bacteroides spp. The organisms recovered in significantly higher numbers in controls were Staphylococcus aureus and Propionibacterium acnes. beta-Lactamase activity was detected in 19 isolates recovered from 15 individuals (9 patients and 6 controls). These findings demonstrate the aerobic-anaerobic polymicrobial flora associated with purulent nasopharyngitis. Further studies are indicated to evaluate the pathogenic role of these organisms in this condition.