Acute upper respiratory tract infections in children may result in overuse of antibiotics as throat culture cannot be performed in every setting and results cannot be obtained early. A rapid and reliable test might decrease unnecessary antibiotic usage. The purpose of this study was to determine the prevalence of group A beta-hemolytic Streptococcus (GABHS) infections in different pediatric age groups and to assess the diagnostic value of rapid antigen detection test (RADT) for streptococcal pharyngitis. This study was performed in a pediatric outpatient clinic. All children who were admitted with signs and symptoms of acute upper respiratory tract infections were included in the study. Throat culture and RADT were performed and prevalence of GABHS was assessed. Diagnostic value of RADT was determined. This study included 1248 children with a mean age of 6.3 +/- 3.6 years. There were 655, 518, and 75 children in age groups of 0-6, 7-12 and 13+ years, respectively. The overall prevalence of GABHS was 38.1% (475/1248), as judged by throat culture. The prevalence was highest in the 7-12-year age group (53.9%) and lowest in the 0-6-year age group (25.2%). Considering all patients, RADT gave a sensitivity of 89.7%, specificity of 97.2%. The sensitivity and specificity of RADT were similar in different age groups (p values > 0.05). Diagnostic value of RADT is high and can be used safety in populations where streptococcal. pharyngitis and its complications such as acute rheumatic fever and acute giomerutonephritis are common. (c) 2008 Elsevier Iretand Ltd. All rights reserved.