Moral distress is a complex and challenging problem that may cause negative biopsycohosical and professional outcomes for critical care nurses. The purpose of this work was to explore the relationship between the ethical climate of the work environment and moral distress as experienced by critical care nurses; and to explore relationships among mediators of stress (nurse characteristics e.g. education (BSN, nonBSN), years certified as a critical care nurse, and tolerance of ambiguity) and their relationship with perceived stress, moral distress, health status and salivary alpha amylase. A descriptive correlational cross-sectional design was used for this pilot study of 100 critical care nurses working in adult intensive care units in one large academic medical center. Data were analyzed using descriptive statistics to characterize the sample and the model variables. Regression analysis using a stepwise regression model building technique was used to determine predictors of the study outcomes (moral distress, health status, and salivary alpha amylase). The findings demonstrate that the ethical characteristics of the work environment and perceived stress were predictive of moral distress, psychological/emotional outcomes and stress symptoms. Other variables thought to mediate these relationships were not significant. Future research is needed to find ways to prevent moral distress from occurring and to support nurses dealing with moral distress.