Abstract—Among youth with diabetes mellitus, elevated blood pressure represents one of the most common comorbidities. Hence, exploring dietary factors that may help prevent or control hypertension in this population is of paramount importance. We investigated whether adherence to the Dietary Approaches to Stop Hypertension (DASH) diet is associated with hypertension in youth with diabetes mellitus from the SEARCH for Diabetes in Youth Study. Between 2001 and 2005, 2830 youth aged 10 to 22 years (2440 with type 1 and 390 with type 2 diabetes mellitus) completed a study visit. For each of the 8 DASH food groups, a score of 10 was assigned when the DASH recommendation was met. Lower intakes were scored proportionately, and the 8 individual scores were summed. The association between the overall DASH score and hypertension was evaluated using multiple logistic regression. The crude prevalence of hypertension was 6.8% for youth with type 1 and 28.2% for youth with type 2 diabetes mellitus. In youth with type 1, a higher adherence to DASH was inversely related to hypertension, independent of demographic, clinical, and behavioral characteristics (tertile 2 versus 1: odds ratio: 0.7, 95% CI: 0.5 to 1.0; 3 versus 1: odds ratio: 0.6, 95% CI: 0.4 to 0.9; P_trend=0.007). For type 2 diabetes mellitus, the DASH diet was not associated with hypertension (tertile 2 versus 1: odds ratio: 0.8, 95% CI: 0.5 to 1.4; 3 versus 1: odds ratio: 0.9, 95% CI: 0.5 to 1.5; P_trend=0.6). Prospective observational studies or clinical trials are needed to investigate whether adherence to the DASH guidelines may help prevent hypertension in youth with type 1 diabetes mellitus. In type 2 diabetes mellitus, more research with a larger sample is necessary.