BACKGROUND The high prevalence of low nocturnal blood glucose levels is a major problem in the treatment of children with diabetes. METHODS The effect of a beta-glucan-enriched bedtime snack on nocturnal blood glucose levels was examined in comparison with an equicaloric conventional snack in 38 children with diabetes during a 12-night study period. RESULTS A significant influence of the type of bedtime snack on the blood glucose course until 2 AM could be observed (P < 0.05). However, there was no difference in the prevalence of nocturnal hypoglycemic blood glucose levels, which was 27% at 2 AM. CONCLUSION Silent nocturnal hypoglycemia is common in children with diabetes. The introduction of a fiber-enriched bedtime snack may flatten the blood glucose curve before midnight but cannot prevent low 2 AM blood glucose. Other therapeutic strategies that reduce the risk of asymptomatic and symptomatic nocturnal hypoglycemia would be beneficial to many children with diabetes.