Objective (s): Recent increases in pediatric abdominal obesity suggest that children and adolescents should be assessed anthropometrically as a step toward managing their long-term cardiovascular risk status. This study was conducted to investigate the relationship between waist-to-height ratio and blood pressure in adolescent girls in Kashan, Iran. Methods: This was a cross-sectional study. A sample of 1046 girls aged 11-19 years participated in the study and their height, waist circumference, systolic blood pressure (SBP) and diastolic blood pressure (DBP) were measured. Waist-to-height ratio was calculated by dividing the waist to height. Abdominal obesity was defined WHtR > 0.5. Blood pressure in all girls who had high blood pressure in the first visit, again was measured in second visit and if their blood pressure was high in the second visit, again their blood pressure was measured in other visit (third time) and the average of the three blood pressure was considered as their established blood pressure. Hypertension and prehypertension was defined according to percentiles of age- sex and height presented by the fourth report on the diagnosis, evaluation and treatment of hypertension of children and adolescents. The findings were analyzed using descriptive and analytical statistics by of spss16 software. Results: The prevalence of prehypertension and hypertension were 6.8% and 7.3% respectively and 24.6 percent of participants had waist-to-height ratio greater than 0.5. ANOVA test showed positive relation between the mean of systolic-diastolic blood pressure and waist-to-height ratio (p <0.0001), so that with increasing waist-to-height ratio, mean of systolic and diastolic blood pressure increases. Conclusion: The results of study showed that there was relationship between the mean of systolic and diastolic blood pressure and waist-to-height ratio among adolescents and abdominal obesity was associated with increasing risk of hypertension.