This study was an exploratory investigation of the extent and nature of nurses' reported participation in the resolution of treatment dilemmas for infants with severe congenital anomalies. Participants in the study were 83 registered nurses from neonatal intensive care units in five large urban hospitals in the Southwest. Data were collected through the use of intensive semi-structured interviews with each participant and nurse responses to an investigator designed case study instrument, The Nursing Ethical Decision-Making Scale. Results indicated that a majority (85%) of the nurses in the study do not participate in a substantial way in decisions to initiate or forego life-sustaining treatment for their infant patients, yet they bear the major responsibility for implementing those decisions. The lack of participation in the decision-making process was cited by 70% of the nurses as being a major source of occupational stress and ethical anguish. Nurses with graduate educational preparation or advanced clinical practitioner education tended to take a more active role in decision-making. Other factors that appeared to promote participation in decision-making included nurse perceptions of administrative support for involvement, the existence of internal mechanisms for communication about treatment dilemmas (including infant care review committees), and hospital affiliation with a medical school. Eighty-seven percent of the nurses identified themselves as the infant's primary advocate, but only 20% of that group reported that they would pursue decisions through the chain of command outside the neonatal unit if they believed that an infant was not receiving appropriate treatment.