The frequency of cesarean deliveries for women attended by certified nurse-midwives in the United States (1.8-10.4%) is lower than the rate for the general population of woman who gave birth in the United States in 1990 (23%). This paper describes the research that reported cesarean birth rates for certified nurse-midwives. Major methodology limitations of the research suggest that significant information gaps exist regarding nurse-midwifery care and its effect on cesarean delivery. Issues surrounding this common clinical procedure are complex, with its high cost and controversy over determinant factors. It is important to develop convincing evidence about the influence of nurse-midwives' care on reducing the frequency of cesarean delivery in the United States.