Background: Hypertension diagnosis in children is difficult because of the multiple sex, age, and height-specific thresholds to define elevated blood pressure (BP). Blood pressure-to-height ratio (BPHR) has been used to facilitate the identification of elevated BP in children. Methods: From January to June 2017, a cross-sectional study was conducted for 830 adolescents aged 12 to 15 years in Abu Kabir city, Sharkia governorate, Egypt. Blood pressure tables from the National High Blood Pressure Education Program (NHBPEP) Working Group on High Blood Pressure in Children and Adolescents were used as our standard of comparison. Sex-specific systolic and diastolic blood pressure-to-height ratios (SBPHR and DBPHR) were calculated. Receiver operating Characteristic (ROC) curve analyses were performed to assess the accuracy of BPHR for discriminating between hypertensive and non-hypertensive adolescents. Results: The prevalence of prehypertension and hypertension were 8.4% and 4.9% respectively. Optimal SBPHR and DBPHR thresholds for defining elevated BP were 0.741 and 0.475 in males, respectively, and 0.750 and 0.494 in females, respectively. The sensitivity of SBPHR and DBPHR in both sexes was all above 93%, and specificity in both sexes was above 94%. Positive predictive value for SBPHR and DBPHR was 76.4% for both in males; and 71.4% and 71.6% in females respectively; negative predictive values in both sexes were all above 98%. Conclusions: BPHR is a simple screening tool with high sensitivity and specificity for screening hypertension in adolescents.