Background:Aims were to investigate sex, ethnicity, and age differences in achieving daily step count and television (TV) watching recommendations in schoolchildren.Methods:Participants were 615 children (n = 325) and adolescents (n = 290) aged 5 to 16 years. Activity was assessed over 5 days using pedometers; TV time was collected via parental proxy-report and self-report. Ethnic, sex, and age differences in step counts, TV time, and odds of meeting TV and step count recommendations were examined for weekdays, weekend days, and overall using generalized estimation equation modeling.Results:Overall, boys were more active than girls (P < .001). Adolescents were more active than children (P = .044), watched more TV (P = .005), and were less likely to meet TV watching recommendations (P = .004). Non-European children watched significantly more TV (P = .008), and were significantly less likely to meet TV recommendations than non-European children (P = .001). Participants watched more TV and accumulated less steps on weekend days than weekdays.Conclusions:Multifaceted interventions focusing on both increasing activity and decreasing TV time are needed, especially on weekends. Children and girls may benefit more from activity interventions, while ethnic-specific interventions focusing on TV habits may be most efficacious for adolescents.