Diagnosis of acute tonsillitis is clinical, and it can be difficult to distinguish viral from bacterial infections. Rapid antigen testing has a very low sensitivity in the diagnosis of bacterial tonsillitis, but more accurate tests take longer to deliver results. Bacteria are cultured from few people with tonsillitis. Other causes include infectious mononucleosis from Epstein-Barr virus infection, cytomegalovirus, toxoplasmosis, HIV, hepatitis A, and rubella.We conducted a systematic review and aimed to answer the following clinical question: What are the effects of tonsillectomy in children and adults with acute recurrent or chronic throat infections? We searched: Medline, Embase, The Cochrane Library and other important databases up to November 2006 (BMJ Clinical evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA).We found nine systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions.In this systematic review we present information relating to the effectiveness and safety of the following interventions: antibiotics, cold steel tonsillectomy, diathermy tonsillectomy.