BACKGROUND: Children with adenoid hypertrophy have been shown to harbor pathogenic bacteria in the nasopharynx despite antibiotics. Removal of the adenoid is associated with a reduction in the bacterial count. AIMS: The study was done to determine the bacteriology of the adenoid tissue in chronic adenotonsillitis and adenoid hypertrophy, and determine the antibiotic sensitivity of potential pathogens. MATERIALS AND METHODS: This is a descriptive study conducted on 100 patients aged between three and twelve years who underwent adenotonsillectomy/adenoidectomy. After adenoidectomy, the specimen along with the swab taken from the surface of the adenoid was sent for microbiological examination. After 48 and 96 hours, the microbial growth was identified and the antibiotic-sensitivity pattern of the isolate was studied. RESULTS: Aerobic organisms grew in 93% of the specimens and anaerobic organisms in 68%, whereas 7% had no growth. The surface was predominated by commensals and the pathogens were mainly found in the core. The predominant pathogens were Staphylococcus aureus, Streptococcus pneumoniae, and Enterococcus species. The organisms were resistant to penicillin but showed sensitivity to co-amoxiclav and ciprofloxacin. Co-amoxiclav and ciprofloxacin should be considered as the first line of medical treatment for adenotonsillar diseases. CONCLUSIONS: Infection is the main cause of adenoid hypertrophy. Amoxicillin with potassium clavulanate and ciprofloxacin should be considered as the drugs of choice for all adenotonsillar diseases. Early and prompt treatment of adenoid hypertrophy with appropriate antibiotics will avoid unnecessary exposure to repeated antimicrobial therapy, thereby maintaining the beneficial effects of the normal adenoid flora.