Diabetes is a common and costly disease with severe complications. Despite evidence that tight control of blood sugar prevents complication, only about 40% of patients with diabetes have adequate blood sugar control. Approximately 75% of all patients with diabetes have concurrent hypertension, and despite evidence that aggressive blood pressure control prevents complications in diabetes, only approximately 25% of all hypertensive patients with diabetes have their blood pressure (BP) under effective control. Therefore, in the management of diabetes, these two outcomes, blood sugar and blood pressure, are of paramount importance. A single, systematic approach to improving control of both these parameters would drastically lessen the burden of diabetes on society. Using an adapted version of the Health Decision Model as our theoretical model to identify predictors of treatment adherence, this study group has developed a telephone- administered, tailored patient health education and behavioral intervention designed to improve control of both blood pressure and blood sugar for patients with both diabetes and hypertension. The intervention uses behavior change models, including the trans- theoretical model, social cognitive theory, and precaution adoption theory, in an effort to improve patients' control of their diabetes and concurrent hypertension. This proposed 400-subject, five-year randomized, controlled trial will systematically evaluate the effectiveness of this intervention in a community-based primary care setting among patients diagnosed with both diabetes and HTN. This trial will improve patient self-management of both blood sugar and blood pressure, with the intent of improving control of both outcomes. The trial will also measure the effect of the intervention on self- efficacy, weight loss, physical activity, and medication adherence. Finally, the costs of the study will be measured, as will the effect of the intervention on health services utilization. Project Narrative: Diabetes and hypertension co-exist in approximately 10 million people in the USA and constitute severe risk factors for the development of such complications as heart and kidney disease. We propose a randomized controlled trial in patients of community primary care practices to study a tailored telephone-administered behavioral intervention to improve control of blood pressure and blood sugar in patients with both hypertension and diabetes. If successful in improving control of these diseases this intervention can easily be adopted in other community primary care practices to lessen the burden of diabetes and hypertension in the USA.