Purpose: The purpose of this study was to identify the effects of a simulation-based education on self-confidence and clinical competency for nursing students. Method: The study used a one group pre-post test design. Simulation-based education included pre-discussion, skill training, taking a high-fidelity simulation with METIman and being debriefed during 15 weeks. The pre-test and post-test were conducted to compare the differences in self-confidence and clinical competency. Result: After students had received the simulation-based education they showed statistically significant higher self-confidence(t=-2.215, p=.039) and clinical competency(t=-4.749, p<.001) than before. Conclusion: This study showed that self-confidence and clinical competency were significantly improved by the simulation-based education. Further studies are needed to increase generalizability using valid measurements to assess the main outcomes.