BACKGROUND: Sore throat is a very common reason for people to attend for medical care. Sore throat is a disease that remits spontaneously, that is, 'cure' is not dependant on treatment. Nonetheless primary care doctors commonly prescribe antibiotics for sore throat and other upper respiratory tract infections. OBJECTIVES: To assess the benefits of antibiotics in the management of sore throat. SEARCH STRATEGY: Systematic search of the literature from 1945 to 1999, using electronic searches of MEDLINE (using the keywords, "pharyngitis", "sore throat" and "tonsillitis") after 1966, the Cochrane Library, the Cochrane collection of hand-searched trials, and the reference sections of the articles identified. Abstracts of identified articles were used to determine which studies were trials. SELECTION CRITERIA: Trials of antibiotic against control with either measures of the typical symptoms (throat soreness, headache or fever), or complications (suppurative and non-suppurative) of sore throat. DATA COLLECTION AND ANALYSIS: RevMan 4.0.3 MAIN RESULTS: A total number of 10,484 cases of sore throat have been studied. 1. Non-suppurative complications There was a trend for protection against acute glomerulonephritis by antibiotics, but insufficient cases were recorded to be sure of this effect. Several studies found benefit from antibiotics for acute rheumatic fever, which reduced this complication to less than one third (OR = 0.30; 95% CI = 0.20-0.45). 2. Suppurative complications Antibiotics reduced the incidence of acute otitis media to about one quarter of that in the placebo group (OR = 0.22; 95% CI = 0.11-0.43) and reduced the incidence of acute sinusitis to about one half of that in the placebo group (OR = 0.46; 95% CI = 0.10-2.05). The incidence of quinsy was also reduced in relation to placebo group (OR = 0.18; 95% CI = 0.08-0.43). 3. Symptoms Symptoms of headache, throat soreness and fever were reduced by antibiotics to about one half. The greatest time for this to be evident was at about three and a half days (when the symptoms of about 50% of untreated patients had settled). About 90% of treated and untreated patients were symptom-free by one week. 4. Subgroup analyses of symptom reduction Subgroup analysis by age; blind vs unblinded; us of antipyretics; or results of swabs for Streptococcus yielded no significant differences. REVIEWER'S CONCLUSIONS: Antibiotics confer relative benefits in the treatment of sore throat. However, the absolute benefits are modest. Protecting sore throat sufferers against suppurative and non-suppurative complications in modern Western society can only be achieved by treating many with antibiotics who will derive no benefit. Antibiotics shorten the duration of symptoms, but by a mean of only about half of one day at day 3 (the time of maximal effect), and by about eight hours overall.