Surface and 'core' tonsillar specimens were collected from 60 children, between 2 and 14 years of age, suffering from recurrent tonsillitis, in order to establish the reliability of surface tonsillar swabbing technique and to define the most frequently involved aerobic and anaerobic microorganisms. From the qualitative point of view, the same mixed aerobic and anaerobic flora were obtained in both samples thus demonstrating the reliability of the surface swabbing technique. From the quantitative point of view, 187 microorganisms, 129 (69.2%) aerobes and 58 (30.8%) anaerobes were isolated from surface cultures while 184, 109 (59.2%) aerobes and 75 (40.8%) anaerobes from the core cultures, thus demonstrating a greater number of anaerobes in the core of the tonsil. The most common isolated aerobic microorganisms were the alpha- and beta-hemolytic Streptococci, the Neisseriae and the Staphylococcus aureus; the predominant anaerobic ones were the Fusobacterium nucleatum, the Bacteroides sp. and the Veillonella parvula. The isolated staphylococcus aureus and the bacteroides sp. were all beta-lactamase producers.