The diagnostic approach to sore throat and its treatment by 7 doctors was studied in 692 community clinic patients. Redness of the throat, the commonest clinical feature in all age groups, was present in 88%. The prevalence of other clinical findings varied in the different age groups. 54% of the patients, most of whom were less than 13 years old, were treated initially with antibiotics. Most of the physicians prescribed penicillin V (average, 8.4 days). From 11 (13%) of the throat cultures taken from children under the age of 4, beta hemolytic streptococci (BHS) were grown. Based on throat cultures, antibiotics had been given unnecessarily in 53% of those in whom it was initially prescribed, and wrongly withheld in 10% of those who initially did not receive them. This study reveals an urgent need for a rapid and accurate method of detecting BHS in patients with sore throat.