BACKGROUND: Caries risk assessment is an important tool in clinical decision making. AIM: To evaluate longitudinal changes in caries risk profiles in a group of schoolchildren in relation to caries development. DESIGN: The Cariogram model was used to create caries risk profiles and to identify risk factors in 438 children being 10-11 years at baseline. The assessment was repeated after 2 years and the caries increment was recorded. The frequency of unfavourable risk factors were compared between those considered at the lowest and the highest risk. RESULTS: Fifty percent of the children remained in the same risk category after 2 years. One third of the children were assessed in a higher-risk category while 18.4% showed a lower risk. Those with increased risk compared with baseline developed significantly more caries than those with an unchanged risk category. The most frequent unfavourable risk factors among those with high risk at baseline were high-salivary mutans streptococci and lactobacilli counts as well as frequent meals. CONCLUSION: Half of the children showed a changed risk category after 2 years, for better or for worse, which suggests that regular risk assessments are needed in order to make appropriate decisions on targeted preventive care and recall intervals.