One hundred children and twenty adults were randomly allocated to guillotine or dissection tonsillectomy operations. The study was prospective and double-blind. In the children, the guillotine technique had demonstrable advantages over the dissection technique in terms of duration of operation, blood loss and post-operative pain. There was no significant morbidity in either group. In the adults, the random allocation of patients into these groups was found to be technically unsatisfactory and this arm of the study was abandoned after twenty patients.