A surgical cure for adult obstructive sleep apnoea syndrome (OSAS) is an attractive alternative to nasal continuous positive airway pressure, but current research suggests that uvulopalatopharyngoplasty is not effective in all patients. No subgroup of these patients, who might benefit from surgery to the oropharynx, has as yet been identified. In this study we examined the results of tonsillectomy either as an isolated procedure or as part of uvulopalatopharyngoplasty in seven patients, who had tonsillomegaly. In all seven there was a short-term improvement between the pre-operative and post-operative apnoea/hypoapnoea (A/H) index (100-65 per cent), which could not be accounted for by change in the body mass index (BMI). In one patient a diagnosis of Non-Hodgkin's lymphoma was made from histological examination of the tonsils. The results suggest that adult patients with tonsillomegaly may represent a subgroup of patients with OSAS, who would benefit from surgery aimed at the oropharynx.