The purpose of this study was to evaluate the effect of teaching decision analysis on nursing students' ability to prioritize clinical interventions given the probabilities for the decision situation. Sixty-eight university nursing students were randomly assigned to one of two groups. The 37 nursing students in the experimental group received a 4-hour didactic and interactive teaching session on decision analysis. The 31 nursing students in the control group also received a 4-hour interactive session on a nondecision analysis topic. A posttest experimental design was selected to minimize testing bias. Three clinical case studies were developed, tested, and utilized for data collection. Subjects in the experimental group selected clinical decisions that were in accordance with clinical decisions made by experts more often and more consistently than did subjects in the control group (p less than .0001).