The objective of this study was to assess the impact of an education intervention for primary health care physicians, based on the knowledge of clinical practice guidelines and availability of rapid antigen detection test for group A streptococci (GAS), on the improvement of antibiotic prescription for patients with acute respiratory tract infections. Before and after the intervention, physicians collected data from ten consecutive patients who attended during a 3-week period. This process was performed twice a year for 6 consecutive years (2012-2017). A total of 18,001 patients were visited by 391 primary care physicians during the study period, 55.6% before intervention and 44.4% after intervention. After intervention, the antibiotic prescription decreased significantly, from 33.0 to 23.4% (p < 0.01). However, there was a statistically significant increase (p < 0.01) in the use of penicillins. This study, carried out in daily practice conditions, confirms that the educational strategy was associated with an overall reduction in the use of antibiotics and an improvement in the antibiotic prescription profile in acute respiratory tract infections.