The overall aim of this study was to examine the effects of a high-fidelity simulation on the knowledge and self-confidence of a total of 177 undergraduate nursing students in recognizing and responding to hypovolemia. A randomized experimental pre-and post-test research design with a process evaluation was employed. A significantly larger proportion of students in the intervention group than in the control group increased the number of correct responses in their knowledge and levels of self-confidence postintervention. As enablers for the successful implementation of the intervention, a need for a safe environment, fidelity, and learning in different roles were identified.