In Japan, there is a higher incidence of childhood obesity in the Tohoku district than in other areas. It is known that reduced physical activity is associated with increased body weight, but little is known about the physical activity patterns of children in this area. Accordingly, this study was designed to measure the physical activity of 145 children (73 boys and 72 girls) in Hashikami Town, Aomori Prefecture. Physical activity was assessed through a questionnaire as well as through two weeks of pedometer use. Boys spent more time engaging in physical activity than girls did, reporting 9.5 (0.6–22.0) versus 7.0 (1.2–21.5) hours per week [median (range)] (p=0.002). On school days, boys took an average of 13,586±4,386 (mean±SD) steps per day, while girls took 12,248±4,112; on holidays, boys took 9,531±4,557, while girls took 9,419±4,524. There was no significant sex-based difference in the number of steps per day (F=1.197, p=0.276), but both boys and girls significantly reduced the number of steps they took on holidays (F=116.537, p<0.001). In addition, 36 (24.8%) children reduced the number of steps they took by more than 50% on holidays compared to school days. In general, the participants engaged in the internationally recommended amounts of physical activity. Yet their reduced level of physical activity on holidays seems to be a matter for concern, as it is a possible cause of the higher incidence of childhood obesity in this area.