The objective of this study was to evaluate the frequency of infection of pharyngeal mucosa, palatal and pharyngeal tonsils with types 6, 11, 16, 18, 31, and 33 human papilloma virus (HPV). A total of 57 children (30 boys and 27 girls) aged from 2 yr 10 mo to 14 yr 5 mo (mean 82+/-28.9 months) were examined. The patients were hospitalized for preplanned adenotomy, tonsillotomy or tonsillectomy. None of them exhibited clinical signs of recurrent respiratory papillomatosis. DNA of HPV was detected by means of the polymerase chain reaction (PCR assay) in mucosal cells obtained by scraping from the posterior pharyngeal wall (57 samples) and in biopsies from palatal (8 samples) and pharyngeal (52 samples) tonsils. The presence of HPV DNA was documented in 24 of the 57 (42.1%) children. In was found in ten (17.5%) samples from mucosal cells of the posterior pharyngeal wall, in pharyngeal tonsil biopsies from 16 of the 52 (30.8%) children, and in palatal tonsil biopsies from one of the 8 (12.5%) patients. Type 6 HPV was identified in 8 (14%) children, type 11 HPV in 1 (1.7%), type 16 HPV in 5 (8.8%), type 31 in 4 (7%), and type 33 in 12 (21%) patients. None of the samples contained type 18 HPV. Two types of HPV were simultaneously found in 4 (7%) children and three types in one patient. The frequency of HPV infection was comparable in children of preschool and school age.