This article used a within-subjects pre- and post-test comparison design to verify the impact of metacognition on clinical judgment and clinical competence in simulations using blended learning for nursing students. The study participants were 56 nursing students in their 4th year of college. The metacognition score of the participants for this study was not statistically significant. The differences in clinical judgment score and clinical competence scores reached statistical significance (t=-13.76, p=<0.001; t==-9.06, p=<0.001). Post-learning, the difference in clinical judgment score among 3 metacognition groups was statistically significant (F=3.76, p=0.029). The differences in clinical competence score among 3 metacognition groups pre- and post-test were statistically significant (F=3.87, p=0.027; F=6.09, p=0.004).