The relationship between consumption of a confectionery snack after an overnight fast and cognitive function was examined using a variety of cognitive tasks, including spatial memory, verbal memory, attention, visual perception and short-term memory, in a sample of 21 boys, ages 9-12 years. Performance on the vigilance attention task was significantly improved when the participants consumed a confectionery snack compared to consumption of a noncalorie snack. Participants had significantly higher hit rates and significantly lower miss rates after the confectionery snack. In addition, false alarm rates increased as a function of time for the placebo condition and decreased for the confectionery condition. Thus, the confectionery snack enhanced ability to stay on task for an extended period of time, enabling the children to more accurately identify target information, as well as correctly reject nontarget information. Analysis of the types of errors made also revealed that when the children were in the confectionery condition they were less likely to make more glaring errors. No significant differences were found in tests of digit span, verbal memory, spatial memory or visual perception.