The University of Miami proposes to participate as a clinical center in the African American Study of Kidney Disease (AASK) to compare the efficacy of double-masked administration of randomized antihypertensive drugs on blood pressure control and progressive renal disease. A team of physicians and paramedical personnel, most of whom were involved in the NIH sponsored Modification of Diet in Renal Disease Study and experienced in the longterm care of patients with hypertension and renal disease, is committed to an effective conduct of the Study. An administrative center within the Division of Nephrology and an outpatient clinic center will be dedicated to the AASK Miami team. The Clinical Research Center will be used for patients requiring hospitalization. Laboratory, pharmacy and radiopharmacy support will be provided by the University of Miami Hospital and Clinics. Potentially eligible African-American men and women can be identified on- campus from the Renal and Hypertension, General Medicine, and family Medicine Clinics at the University of Miami/Jackson Memorial Medical Center, and the Renal and Hypertension Clinics at the Miami Veterans Administration Medical Center, and the Clinics of UM Care and Jackson Memorial Medical Center Health Plans. Enrollment of patients will also be sought off-campus from nephrologists in practice, the Association of Black Cardiologists, the Dade County Medical Association, local HMO's, family medicine practice groups, and directly, through local advertisement within the African-American community through newspapers, radio, television, churches, social organizations, and the Dade County School District. The population available and the interest in the Study by patients and physicians alike indicate that 65 selected volunteer patients with hypertension and chronic renal disease from arteriolar nephrosclerosis can be entered, randomized and followed in Miami. The Miami team is committed to accept and implement the common protocol and procedures approved by the Steering Committee and NIDDK staff.