The purpose of this study was to investigate the quality (reliability and validity) of large-scale fitness testing in Texas and determine if reliabilities and validities were related to potential confounding variables. Four test administration scenarios were conducted to investigate the quality of data collected statewide as part of the Texas Youth Evaluation Project. Teachers and/or expert test administrators tested individual students (N = 1,010) on two occasions. Criterion-referenced reliabilities were very good to generally acceptable for all FITNESSGRAM[R] test items, with musculoskeletal items having the lowest reliabilities. The validity of teacher-administered tests was good. Reliability and validity of teacher-obtained health-related fitness measures were generally unrelated to potentially confounding student or school characteristics. Administrators, teachers, parents, and students can feel comfortable with the reliability and validity of the statewide health-related fitness testing in Texas. (Contains 1 note and 5 tables.)