Knowledge of how cesarean birth rates vary by hospital characteristics may aid in understanding and perhaps modifying some of the structural and process components of newborn delivery services to decrease the necessity of birth by cesarean procedure. To examine the influence of select hospital characteristics, data on hospital newborn deliveries in Illinois for 1986 among women 10-50 years of age inclusive (N = 130,249) were obtained from computerized hospital discharge abstract files. Characteristics of the hospitals were obtained from the annual American Hospital Association survey. Adjusting for mother's age at delivery; presence of pregnancy, labor, and delivery complications; expected primary payer; and size of hospital, women delivering in hospitals with teaching status were less likely (odds ratio = 0.76, p less than .001, 95 percent CL: 0.73, 0.79) to have a primary cesarean birth than women delivering in hospitals without this designation. A significantly lower cesarean birth rate in teaching hospitals was also observed in women of all age groups, in Medicaid and non-Medicaid women, and for most categories of delivery complications. These data suggest the need to identify the programmatic, technologic, and manpower functions associated with hospital teaching status that could decrease the likelihood of a primary cesarean delivery. The study also suggests that changes aimed at the manner of diagnosis, monitoring, and/or management of pregnancy/delivery complications may reduce the cesarean birth rate because of large differences in the primary cesarean birth rate found between teaching and other hospitals for most categories of newborn delivery complications.