The short-term aftereffects of a bout of moderate aerobic exercise were hypothesized to facilitate children’s executive functioning as measured by a visual task-switching test. Sixty-nine children (mean age = 9.2 years) who were overweight and inactive performed a category-decision task before and immediately following a 23-min bout of treadmill walking and, on another session, before and following a nonexercise period. The acute bout of physical activity did not influence the children’s global switch cost scores or error rates. Age-related differences in global switch cost scores, but not error scores, were obtained. These results, in concert with several studies conducted with adults, fail to confirm that single bouts of moderately intense physical activity influence mental processes involved in task switching.