Purpose: The purpose of this study was to identify the effect of simulation-based education for nursing students. Methods: One group pre-post test of quasi-experimental design was used. Forty-four nursing students participated in the study. The instruments used for this study were critical thinking disposition scales and problem solving process scales, clinical competency scales. Data were analyzed using the SPSS 18.0 program with descriptive statistics, paried-test. Results: There were significant increases in critical thinking(t=5.958, p<.001), problem solving process(t=3.331, p=.002) and nursing clinical(t=2.226 p=.031). Conclusion: In conclusion, the simulation-based education program was effective in contributing towards the development of critical thinking, problem solving process and clinical competence. Further study is needed to develop of clinical based learning modules and determine the effect of simulation method, learning times, team size on learrning.