Introduction. Using rapid antigen diagnostic tests (RADTs) in clinical practice has shown excellent specificity but often has diminished sensitivity. Gap Statement. Local data for evaluating the diagnostic performance of a new fluorescence-based RADT and its influence on the antibiotic prescription rate are not available. Aim. To evaluate the accuracy of fluorescent immunoassay (FIA)-RADTs for diagnosing group A streptococcal (GAS) pharyngitis among children and its estimated effect as a point of care test (POCT) on the antibiotic prescription rate at the paediatric emergency department. Methodology. A prospective study was conducted, comprising children 3 to 14 years old presenting with pharyngitis. Throat swab culture and FIA-RADTs were performed on all samples. Conventional PCR was performed on the discordant samples. Results. A total of 246 children were included in this study. The sensitivity, specificity, and positive and negative predictive values of the FIA-RADT, based on culture results and PCR detection combined, were 95.6, 96.8, 94.6 and 97.4 %, respectively. Antibiotics have been prescribed to 162 (65.9 %) children; however, if FIA-RADTs had been added in the clinical practice as a POCT, only 92 (37.4 %) children would have received antibiotics in total. Additionally, implementation of FIA-RADTs would significantly reduce the antibiotic prescription rate from 48.8 and 60.6 % to 9.5 and 31.9 % among patients with clinical scores of 2 and 3, respectively. Conclusion. The new FIA-RADT is simple, prompt and reliable. It is helpful in clinical settings and may be used to reduce antibiotic overprescription, especially for children who have a low risk for GAS pharyngitis, according to the clinical score.