Hypertension and diabetes are overrepresented in the African-American population and can be particularly devastating in this population. These diseases share genetic predisposition, medical risk factors, and environmental influences as etiologic factors, and they may be interrelated, at least in part, by obesity and accompanying hyperinsulinemia. Noncompliance with treatment plans is a significant barrier to health improvement in both diseases, but increased attention to patient involvement in care is a potential solution to this long-standing problem. The Baltimore Alliance for the Prevention and Control of Hypertension and Diabetes was established in January 1998 to promote care to the underserved community of West Baltimore, Maryland, and to improve outcomes of hypertension and diabetes. Based at the University of Maryland School of Medicine, the Baltimore Alliance comprises a community health worker program, a church-based education and screening effort, managed care and pharmaceutical company (Hoechst Marion Roussel) partners, a health policy and services research group, and inpatient/outpatient clinical care sites in the health system. Mobilization, cultural relevance, and partnership are employed to ensure that the Alliance's goals of increased patient enrollment and retention in treatment programs will be achieved. Thereby, improved outcomes--clinical, humanistic, and economic--will result. Novel as well as classic approaches to patient education, compliance, and goal achievement are being pursued. Complete expert systems for hypertension and diabetes disease management are being created and will be implemented in the near future. Baseline practices and current outcomes are being identified to act as historical controls. The organization and administration of the Alliance will serve as a prototype that others may follow.