Background: School physical education (PE) programs provide a prime environment for interventions that attempt to develop school-aged children's motor competence and overall physical fitness, while also stimulating competence motivation to engage in physical activity during childhood. It is generally recognized that a pedometer-based intervention strategy combined with a goal-setting strategy may be effective in increasing physical activity participation among school-aged children. The purpose of this study was to evaluate the impact of an 8-week pedometer-based goal-setting intervention on children's motivation in PE, motor competence, and physical activity. Methods: A pretest-posttest comparison group design was used with the 8-week intervention (3 days/week for 24 sessions). Participants were 273 (boys = 136, girls = 137) students recruited from 3 elementary schools in the US. Classes in each school were randomly allocated to three experimental conditions: (1) an intervention group with a personalized pedometer weekly target to reach in their PE class (N = 110), (2) an intervention group with the fixed pedometer target range to reach in each PE class based on the recommended criteria (N = 90), or (3) a control group without intervention (N = 73). Analysis/results: The factorial repeated measures MANOVA indicated significant multivariate effects for the group [F(6, 528) = 12.954, p < 0.001]. "Post hoc" analyzes showed that both experimental groups had significantly higher expectancy-value beliefs, motor competence, and physical activity compared to the control group (p < 0.001). Conclusions: Health practitioners should be aware that goal-directed action can contribute to school students' PE-related achievement motivation, motor competence, and achieving the recommended 60 min of moderate-to-vigorous physical activity.