The Numerical Rating Scale-11 (NRS-11) is one of the most widely used scales to assess self-reported pain intensity in children, despite the limited information on its psychometric properties for assessing pain in pediatric populations. Recently, there has been an increase in published findings regarding the strengths and weaknesses of the NRS-11 as a measure of pain in youths. The purpose of this study was to review this research and summarize what is known regarding the reliability and validity of the NRS-11 as a self-report measure of pediatric pain intensity.