This study suggests that nurses' perceptions of pediatric oncology phase I clinical trials are diverse and mixed but are more likely to be positive than negative. Improving future treatments, medical benefit, improved quality of life, and hope were cited as potential benefits of phase I clinical trials, but nurses felt that families were hoping for a cure. Toxicities, false hope, and decreased quality of life were perceived as potential negative outcomes. Acting as a patient advocate was viewed as the most important nursing role, and providing information was identified to be the most important purpose of informed consent. Although not statistically significant, data suggest that age, experience, and practice setting may influence nurses' perceptions. Younger or less experienced nurses were more likely to report either positive or negative perceptions, whereas older or more experienced nurses expressed mixed or moderate perceptions. Inpatient nurses reported more negative perceptions compared with outpatient nurses. The respondents report that caring for patients on phase I had both positive and negative effects on their quality of nursing work life.