BACKGROUND AND OBJECTIVES: Acute pharyngitis is a common diagnosis in ambulatory pediatrics. The Infectious Diseases Society of America (IDSA) clinical practice guideline for group A streptococcal (GAS) pharyngitis recommends strict criteria for GAS testing to avoid misdiagnosis and unnecessary treatment of children who are colonized with group A Streptococcus. We sought to improve adherence to the IDSA guideline for testing and treatment of GAS pharyngitis in a large community pediatrics practice. METHODS: The Model for Improvement was used, and iterative Plan-Do-Study-Act cycles were completed. The quality improvement project was approved for American Board of Pediatrics Part 4 Maintenance of Certification credit. Interventions included provider education, modification of existing office procedure, communication strategies, and patient and family education. Outcomes were assessed by using statistical process control charts. RESULTS: An absolute reduction in unnecessary GAS testing of 23.5% (from 64% to 40.5%) was observed during the project. Presence of viral symptoms was the primary reason for unnecessary testing. Appropriate antibiotic use for GAS pharyngitis did not significantly change during the project; although, inappropriate use was primarily related to unnecessary testing. At the end of the intervention period, the majority of providers perceived an improvement in their ability to communicate with families about the need for GAS pharyngitis testing and about antibiotic use. CONCLUSIONS: The majority of GAS pharyngitis testing in this practice before intervention was inconsistent with IDSA guideline recommendations. A quality improvement initiative, which was approved for Part 4 Maintenance of Certification credit, led to improvement in guideline-based testing for GAS pharyngitis.