Background: The age, gender, and height, percentiles requirements for the ‘gold-standard’ diagnosis of hypertension and prehypertension in adolescents make it time-consuming for clinicians and difficult-to-use by non-professionals. Simplified diagnostic tools are therefore needed. The use of blood pressure-to-height ratio (BPHR), systolic (SBPHR) and diastolic (DBPHR), has been reported in Han adolescents, and it requires validation in other racial groups. The diagnostic accuracy of SBPHR and DBPHR in Bhavnagar, Gujarat, India was therefore studied. Methods: From a population of 1000 school going Caucasian adolescents aged 12-18 years from two schools; Blood pressures were measured using standard procedures. Hypertension and prehypertension (HTPHT) were defined according to the 2004 Working Group normative tables. ROC curve analyses were used to assess the diagnostic accuracy of BPHR in defining HTPHT in this population. Sex-specific threshold values for SBPHR and DBPHR were determined and thereafter used to define HTPHT. The sensitivity/specificity of this method was determined. Results: The accuracy of SBPHR and DBPHR in diagnosing HTPHT, in both sexes, was >92%. The optimal threshold ratio for prehypertension was 0.725/0.465 in boys and 0.745/0.465 in girls; while for hypertension, they were 0.765/0.495 in boys and 0.795/0.515 in girls. The sensitivity and specificity of this method was >88%. Conclusions: The use of blood pressure-to-height ratio BPHR is valid, simple, and accurate in this population. Keywords: Adolescents; Blood pressure-to-height ratio; Diagnosis; Prehypertension; Hypertension; Bhavnagar; School