Recurrent acute tonsillitis is a common problem. Despite this, there still remain many controversies regarding aetiology and correct management. The tonsillar microflora of 33 children with recurrent acute tonsillitis studied in 1980 and 58 patients studied in 1989 is presented. A comparison of the microbiology in the two periods studied a decade apart suggests that the pathogenic profile is changing. Haemophilus influenzae increased from 39 to 62% in the deep tonsillar tissue in the decade. There was a concomitant increase in incidence of Staphylococcus aureus from 6 to 40% of cases. In the same interval, mixed microflora increased from 18 to 52%. Anaerobic organisms were isolated in insignificant numbers. Unique to this study, 44% of H. influenzae isolates in 1989 were beta lactamase producers, increasing from only 2% in 1980. All of the S. aureus were beta lactamase producers. In the majority, the throat swabs grew only organisms commensal to the upper respiratory tract however, the deep tonsillar tissue excised at tonsillectomy carried significant growths of pathogenic organisms confirming the inadequacy of the superficial tonsillar swab as an indicator of treatment.