The Systolic Hypertension in the Elderly Program (SHEP) encompasses two clinical trials--a pilot study and a full-scale trial--investigating the safety and efficacy of antihypertensive therapy for patients aged 60 years and over with isolated systolic hypertension (ISH), that is, systolic blood pressure (SBP) greater than or equal to 160 mmHg and diastolic blood pressure (DBP) less than 90 mmHg. An optimal result of the full-scale trial should lead to recommendations for prescription of effective therapy that preserves the quality of life while reducing the long-term risks of stroke, other cardiovascular disease, and death. This article briefly describes the design, protocol, and organization for the pilot and fullscale SHEP studies. In these trials the nurses help plan study protocol, coordinate patient recruitment, provide patient care, and maintain protocol compliance. In order to accomplish their role in data collection and reporting, they undergo comprehensive training and certification. Nurses utilize the multicenter clinical trial as an opportunity to participate in research, both independently and collaboratively. The specific roles of nurses within these trials, as well as features of these trials that relate to nursing practice and research, are discussed.