To conduct a prospective, consecutive cohort study to evaluate the incidence of allergen-specific and total immunoglobulin E (IgE) in a paediatric population undergoing adenotonsillectomy for sleep-disordered breathing. A total of 64 consecutive patients presenting for adenotonsillectomy at a single centre were recruited over a period of 3months. All patients underwent adenotonsillectomy and had allergen-specific and total IgE serum testing at the time of anaesthesia induction. Pre-operative history and examination were conducted to determine clinical allergy. Caregivers completed the Sleep-Related Breathing Disorder scale of the Paediatric Sleep Questionnaire and the Mini Rhinoconjunctivitis Quality of Life Questionnaire at baseline and at 6 weeks post-operatively. A total of 37 (57.8%) patients had either allergen-specific or total IgE positivity. House dust mite was the most prevalent allergen-specific IgE finding, being present in moderate to high levels in 14 (21.9%) patients. A total of 17 (26.6%) patients had a history of atopy, while 34 (53.1%) had examination findings suggestive of allergy. Neither serum IgE testing nor clinical history and examination were independently associated with residual symptoms post adenotonsillectomy. Patients with concomitant serum IgE positivity and clinical allergy had higher residual symptom scores compared to those who did not using both Sleep-Related Breathing Disorder scale of the Paediatric Sleep Questionnaire (P=0.035) and Mini Rhinoconjunctivitis Quality of Life Questionnaire (P=0.02) questionnaires. Our prospective, consecutive cohort of patients reflect a greater incidence of serum IgE positivity compared to historical figures. When utilised with clinical findings on history and examination, serum IgE is a useful adjunct that is associated with greater residual symptoms post-adenotonsillectomy.