Objective The present study was undertaken to investigate the role of neck circumference (NC) in predicting prehypertension in children and adolescents. Methods We conducted a cross-sectional study including 6,802 children and adolescents (3,631 boys and 3,171 girls) aged 5-18 years. Main anthropometric data and related information were collected. Results The prevalence of prehypertension was 14.4%, 16.4% and 17.1% in normal weight, overweight and obese group respectively. Among the participants with normal body mass index (BMI), higher NC was significantly associated with increased odds of prehypertension (OR: 1.439; 95% CI: 1.118 to 1.853) after adjustment for age, gender, BMI and WC. Significant associations between NC and either systolic blood pressure (SBP) (β=0.581 mmHg) or diastolic blood pressure (DBP) (β=0.236 mmHg) were found in the linear regression. No significant ORs were observed either in overweight or in obese categories. Conclusion We concluded that additional measure of NC might expand the ability of BMI for the identification of prehypertension in normal weight children and adolescents.