The purpose of this study was to find the moral distress of critical care nurses, to view the spirituality of critical care nurses, and to examine the relations between the moral distress, spirituality, and other related factors. A descriptive survey was used. As random digits table was used to randomize 104 critical care nurses from all critical care units of a medical center. A moral distress instrument and spiritual orientation inventory were both used as the research instruments. Descriptive statistics, t-test, one-way ANOVA, factor analysis, and canonical correlation analysis were used for data analysis. The important findings were as follows (1) Three factors were extracted and named from moral distress instrument, including action response, honesty, and aggressive care. These factors accounted for 49.9% of the total variance; (2) Seven factors were extracted and named from the spiritual orientation inventory, including awareness of a transcendent dimension, mission in life, love, meaning in life, belief in the sacredness, religious experiences, and materialism. These factors accounted for 53.1% of the total variance; (3) The levels of moral distress was significantly positive correlated with the levels of spirituality; (4) The spirituality factors, such as "love" and "awareness of a transcendent dimension", could affect the "honesty" part of moral distress. Results of this study would provide reliable and valid instruments for nurses and nursing administrators to understand the moral distress among critical care nurses, being a basis for designing spiritual nursing courses and strategies for nurses in clinical practice.