There is increasing evidence that non-specific low back pain (LBP) is common among children and adolescents, but there are few longitudinal studies on this subject. This is a longitudinal prospective study aimed at finding factors associated with the prediction of low back pain in schoolchildren aged 9-12 years, which is a younger age group than has previously been studied. This study was performed on school children in the city of Antwerp, Belgium. A total of 287 children filled out a questionnaire and were examined at the beginning of the study (T1) and 2 years later (T2). The questionnaire asked about back pain, general health, health perceptions, quality of life perceptions, sports, leisure, daily life, school life (weight of satchel.) and some issues related to parents (smoking, LBP). The questionnaire reliability was tested. Logistic regression was used to analyse the data. No predictors for LBP in children could be identified. Using logistic regression techniques, we analysed the children who reported no lifetime episode of LBP at both T1 and T2, the children who did report a lifetime episode at both T1 and T2 and also those who reported a history of LBP at T2 only (New LBP). At T2 there were 51 children (17.8%) reporting suffering at least one lifetime episode of LBP who had not reported such an episode at T1. Only one parameter showed a statistical difference: New LBP was observed significantly more frequently in children who do not walk to school ( P<0.0001). An interesting point of this study is that a number of children who had reported a history of LBP at T1 did not do so at T2. It may be that LBP in children is so benign and its natural history so favourable that the memory of the episode fades away. It is extremely interesting to note that among the few significant variables, those related to general well-being and self-perception of health, are prominent. It appears, therefore, that psychological factors play a role in the experience of LBP in a similar way to what has been reported in adults. Poor self-perception of health (health belief) could be a factor behind the reporting of LBP. Some variables linked to consequences of LBP (absence from school or from gym and visit to a doctor) play a significant role in reporting LBP, which suggests that those "health care" factors may reinforce a feeling of disease severity.