To evaluate the concurrent validity of the PROMIS Pediatric Global Health measure (PGH-7), child-report and parent-proxy versions. Surveys were administered via home computer on two separate occasions (December, 2011 and August/September, 2012) to a convenience sample of 4636 children 8-17 years old and 2609 parents who participated in a national Internet panel. Data analysis included: (1) evaluations of differences in PGH-7 scores between groups defined by sociodemographics, clinical characteristics, and access to health care; (2) associations with 15 PROMIS pediatric measures; and (3) correlations with two health-related quality-of-life instruments, the KIDSCREEN-10 and PedsQL-15. PGH-7 scores were lower for children with chronic conditions, Hispanic ethnicity, low socioeconomic status, and barriers to accessing health care. The PGH-7 showed excellent convergent and discriminant validity with PROMIS pediatric measures of physical, mental, and social health. The PGH-7 was strongly correlated with the KIDSCREEN-10, which assesses positive health, and moderately correlated with the PedsQL-15, which assesses problems with a child's health. The PGH-7 measures global health, summarizing a child's physical, mental, and social health into a single score. These properties make it a useful clinical, population health, and research tool for applications that require an efficient, precise, and valid summary measure of a children's self-reported health status. Future research should prospectively evaluate the PGH-7's capacity to detect change that results from alterations in clinical status, transformations of the healthcare delivery system, and children's health development.