 Hypertension in youth is no longer a rare disease and the number of affected children and adolescents is growing with the evolving pediatric epidemic in the US. Hypertension tracks from adolescence into adulthood and has been linked with preclinical indicators of adverse cardiovascular events in adults. Early prevention and intervention efforts are needed to address this increasing public and individual health problem. Preliminary studies from our research group demonstrate promising short-term effects of a behavioral nutrition intervention emphasizing a diet high in fruits, vegetables and low fat dairy that is also low in fat and sodium the DASH diet on lowering blood pressure BP in adolescents. The purpose of this application is to extend these findings by examining the long term effects of an improved 24-week clinically based behavioral nutrition intervention emphasizing the DASH diet the DASH-4-Teens intervention compared to routine nutrition care intervention on changing diet quality, BP, hypertension status, and vascular function in adolescents with elevated blood pressure. Adolescents with diagnosed pre-hypertension and stage 1 hypertension will be randomly assigned to receive either the DASH-4-teens intervention or routine nutrition care. The DASH-4- Teens intervention will include individual in-person nutrition counseling sessions, behavioral counseling telephone calls, and mailings. Routine nutrition care will include individual in-person counseling sessions on guidelines consistent with the Fourth Pediatric Report of the National High Blood Pressure Education Program. Primary outcomes will be measured in both conditions at 6 months post-treatment and at 1 year follow-up. Adherence to treatment will be measured as diet-related goals met, counseling session attendance, and telephone call and food monitoring completion. Findings are expected to improve the treatment of hypertensive adolescents in the clinical setting and contribute to the enhancement of the cardiovascular health of this population. 