Background & aims: Children's food choices are guided by their preferences. It is established, however, that repeated exposure to a novel food increases children's acceptance. This study investigated how acceptance of an initially liked and disliked snack bar develops in 9-11 year-old children. Methods: 315 children were randomised into three groups: A control group (n = 111) and two groups exposed to an initially liked kamut bar (n = 94) and an initially disliked sea buckthorn bar (n = 110). Acceptance of both bars was tested before and after the exposure period, and on the 9th exposure. Results: Intake of both bars increased significantly in the exposure groups. There was no difference in the control groups' intake or liking of the bars between pre and post-testing. Liking rose significantly for children exposed to the disliked sea buckthorn bar, while this was not observed in children exposed to the liked kamut bar. In a post-test children exposed to kamut bars had higher intake of that bar than non-exposed children. This was also observed for the sea buckthorn bar that was also given significantly higher liking scores by the exposure group. Conclusions: The majority of children exposed to an initially disliked bar increase acceptance after nine exposures to the same level as an initially liked bar. Children repeatedly exposed to a liked bar show stable acceptance.