Controversy exists concerning the role of nurse-midwives in tertiary care centers. By tradition, preparation, and practice, nurse-midwives have not sought to work in the areas of high-risk obstetrics. However with the advent of modern technology and the prevailing economic and legal climate, many more women are finding themselves referred to high-risk centers for obstetrical care. All of these factors contributed to the formation of the nurse-midwifery service at the University of Miami, Jackson Memorial Hospital, Miami, Florida in January 1977. The service is described as it evolved over four and a half years. The success of the model led to the expansion of the philosophy and the development of the three principles of practice–independent management, comanagement, and collaborative management. The nurse-midwives have performed 8,145 deliveries. Selected data is reviewed and the continued role of nurse-midwives in perinatal centers is discussed.