The purpose of this study was to obtain validity evidence for the Physical Activity and Healthy Food Efficacy Scale for Children (PAHFE). Construct validity evidence identifies four subscales: Goal-Setting for Physical Activity, Goal-Setting for Healthy Food Choices, Decision-Making for Physical Activity, and Decision-Making for Healthy Food Choices. The scores on each of these subscales show a moderate to high degree of internal consistency (0.59 ≤ α ≤ 0.87). The Decision-Making for Healthy Food Choice subscale and the Decision-Making for Physical Activity subscale scores show significant convergent validity evidence. These results provide support for using this self-efficacy scale to measure children's perceived confidence to make decisions about healthy eating and physical activity. The PAHFE may be considered to be a useful predictor of both physical activity and eating behaviors.