The purpose of the study was to determine if currently used FITNESSGRAM[R] cut-off scores for the Back Saver Sit and Reach Test had the best criterion-referenced validity evidence for 6-12 year old children. Secondary analyses of an existing data set focused on the passive straight leg raise and Back Saver Sit and Reach Test flexibility scores of 87 boys and 91 girls. The reliability and validity evidence was determined for Back Saver Sit and Reach Test cut-off scores of 7, 8, 9, and 10 inches for the boys and girls separately. Reliability evidence for passive straight leg raise and all Back Saver Sit and Reach Test cut-off scores was good to excellent. The most valid cut-off scores had the highest proportion of correct decisions associated with sensitivity [greater than or equal to]0.67, and false-positive rate [less than or equal to]0.24. Based on moderate validity evidence, the best Back Saver Sit and Reach Test cut-off scores for 6-12 year olds are 8 and 9 inches for boys and girls, respectively. These findings should be cross-validated with other samples. (Contains 4 tables and 4 figures.)