Background: The use of simulation in the teaching of internal medicine nursing is important to ensure patient safety during clinical applications.Aim: This study aimed to examine the effect of simulation applications used in the teaching of the 2nd-year internal medicine nursing course and the perceived self-efficacy levels on anxiety, satisfaction with learning, and selfconfidence in students taking the course at the Faculty of Nursing.Methods: In this study, mixed methods both qualitative and quantitative methods were used. The research was carried out with 127 second-year students at the faculty of nursing between September 2019 and May 2020. Data were collected using Demographic and Descriptive Data Form, Generalized Perceived Self-efficacy Scale, Spielberg State Anxiety Inventory, Student Self-Confidence Scale and Satisfaction Scale. Interview Form consisting of semistructured questions was used for qualitative data. Results:Students' state anxiety level was moderate before the simulation. The pre-simulation anxiety level of the students was higher than the post-simulation level; the generalized perceived self-efficacy was at a good level. Satisfaction and self-confidence regarding the simulation were high after both applications. As students' generalized perceived self-efficacy scores increased, their anxiety levels decreased (except after the first application), satisfaction with learning and self-confidence increased, but academic achievement was not affected. From the qualitative data, two main themes and two sub-themes under each main theme were determined. The main themes were grouped as "Reactions during simulation" and "Self-evaluation after simulation". Conclusion:It was determined that simulation activities were effective in improving the teaching of internal medicine nursing and that these practices positively affected the anxiety and learning satisfaction and self-confidence of those who perceived their self-confidence as high. It is considered that the use of simulation method in internal medicine nursing courses will increase teaching success.