The relation between a history of low-back pain (LBP) and straight leg raising (SLR) was investigated in 267 children (6-13 years) and 135 adolescents (14-18 years). The prevalences of a history of LBP and low mean SLR values were significantly greater in the older age group. In each age group, boys had significantly lower SLR values than girls. No significant difference in straight leg raising was found between those subjects with and those subjects without a history of low-back pain except for male adolescents, for whom there was a significant direct relation between a history of LBP an decreased SLR.