Background: The physical activity vital sign (PAVS) is a simple, validated tool for assessing physical activity in adults that has not been previously studied in pediatrics. Hypothesis: Reported physical activity utilizing the PAVS in pediatric patients should vary according to known associations with physical activity, such as age, sex, blood pressure, and body mass index (BMI). Study Design: Cross-sectional study. Level of Evidence: Level 3. Methods: All patients within a family medicine residency clinic were assessed via the PAVS from October 1, 2015, to October 31, 2016, including 255 consecutive pediatric patients aged 5 to 18 years. Associations were examined between PAVS, age, sex, blood pressure, and BMI using 1-way analysis of variance. Results: The average PAVS reported for youth (5-11 years) was 384.9 ± 218.1 minutes per week, with 69.5% reporting sufficient physical activity (≥300 minutes per week). Adolescents (12-18 years) reported a mean PAVS of 278.3 ± 199.6 minutes per week, with 51.1% reporting sufficient physical activity. Physical activity was lower in older participants (P < 0.0001) and was higher in male patients (P < 0.03). Higher BMI was associated with lower PAVS (P < 0.005), while lower systolic blood pressure was associated with a greater number of days per week of physical activity (P < 0.005). Conclusion: The PAVS successfully identifies accepted associations between age, sex, and BMI in a pediatric population. Clinical Relevance: The correlation of the PAVS with age, sex, BMI, and blood pressure may inform future strategies to address and prevent cardiometabolic disease in pediatric patients.