Thesis advisor: Pamela J. Grace / Nurses working in newborn intensive care units (NICU) report experiencing ethical dilemmas related to treatment decisions for infants in their care. The opportunity for nurses to contribute to the formulation of treatment plans for these infants is increasing, but often nurses are required to implement treatment plans with which they may not agree. This causes conflict for the nurse and has been shown to have implications for the nurse and, ultimately, nursing and healthcare practice. Not taking action to resolve the perceived dilemma is especially problematic on several counts (Raines, 1996). Nurse Activism, the outcome variable, is defined as the range of likely actions nurses may take to resolve ethical dilemmas in practice (Penticuff & Walden, 1987). This cross-sectional study investigated the range of likely actions that nurses would take in response to a hypothetical ethical dilemma. The web-based survey was completed by 224 NICU nurses from seven Massachusetts hospitals. Subjects responded to the Nurses Ethical Involvement Survey (Penticuff & Walden, 1987) and demographic questions. Hierarchical multiple regression analysis found that NICU nurses with greater concern for the ethical aspects of clinical practice (p = .001) and an increased perception of their ability to influence ethical decision-making (p = .018) were more likely to exhibit nurse activism to resolve an ethical dilemma and these findings explained just 8.5 percent of the variance. Future research is necessary to determine other factors contributing to, and inhibiting the actions of, nurses to resolve ethical dilemmas encountered in the NICU. / Thesis (PhD) — Boston College, 2010. / Submitted to: Boston College. Connell School of Nursing. / Discipline: Nursing.