Rulings in recent negligence cases reveal a shift towards what the 'reasonable patient' would expect in deciding the risks doctors must disclose to patients. This survey aimed to investigate whether the 'reasonable patient' and 'responsible body of medical opinion' agree about which risks should be discussed regarding tonsillectomy. Using questionnaires, surgeons were asked which of the 10 complications they routinely discussed and patients were asked how seriously they regarded these complications. The results were compared with the Test of Proportions. Most surgeons routinely mentioned otalgia, odynophagia, throat infection and re-operation. Most patients regarded potentially fatal bleeding, pneumonia and blood transfusion as very serious but only the minority of surgeons mentioned these (P < 0.001). When obtaining consent for tonsillectomy, surgeons do not routinely mention all the risks that the 'reasonable patient' would expect. The 'reasonable patient' would expect that re-operation, transfusion, pneumonia and fatal blood loss are discussed.