Background. Children report low back pain (LBP) as young as 8 years. Preventing LBP in children may prevent or delay adult incidence. Objectives. The purpose of this study was to determine whether education and daily exercise affect LBP episodes in children compared with education alone. Design. This was a prospective, multicenter cluster randomized controlled trial. Setting. The study was conducted at 7 New Zealand primary schools. Participants. Children (n 708), aged 8 to 11 years, from 7 schools stratified by sample size (36, 114, 151, 168, 113, 45, 83) were randomized and allocated to 2 masked groups: intervention (4 schools, n 469) or control (3 schools, n 239). Interventions. Participants in the intervention group were taught 4 spinal movements for daily practice. Both groups participated in education that emphasized back awareness . Measurements. Low back pain history at baseline was assessed. Children reported episodes of LBP during the previous week on trial days 7, 21, 49, 105, 161, and 270. Analysis was at the individual participant level, with adjustment for school clusters.