To find out the factors responsible for variations of adolescent blood pressure, a community-based cross-sectional study was undertaken among 1081 adolescents, aged 10-19 years, selected by simple random sampling in an urban slum of Kolkata, Chetla in 2003-04. Age, educational status, additional ghee/butter intake with diet, family history of hypertension, weight, height and body mass index were found to be associated with blood pressure in unifactorial analysis, hence these variables were considered for multifactorial analysis. All these independent variables were correlated with both systolic and diastolic blood pressure except additional ghee/butter intake with food. In stepwise multiple regression analysis, age, education, family history of hypertension, weight, height and body mass index contributed 64.6% of the total variation of systolic blood pressure, where weight alone contributed to 62.6% while 35.4% of variations remained unexplained. In case of diastolic blood pressure, 56.8% of the total variations were due to age, education, family history of hypertension, weight, height and body mass index, out of which weight alone contributed 56% while remaining 43.2% of total variations remained unexplained. Since single most important predictor of blood pressure was weight, regular aerobic physical activity, dietary modification, behavioral changes and health education are recommended for weight reduction and prevention of obesity.