Background: Simulators-Based Education is any type of educational activity that uses simulation of clinical scenarios to increase students’ awareness and skills. Simulation environments are able to create a place for students to expand their competencies in specialized skills without posing a risk to patients. In simulation, an attempt is made to bring the learning conditions so close to the real conditions, so that the learned concepts can be transferred to the real world.Methods: This is a quasi-experimental study. The statistical populations of the study were nursing and operating room (OR) students of Larestan University of Medical Sciences who were selected using census method. A total of 192 students participated in this study, which 96 students were in the control group and 96 students were in the experimental group. At the beginning of the study, students of both groups participated in the pre-test. In this study low-fidelity simulation was used to train control group, and in the experimental group training, medium- and high-fidelity simulation were applied. The post-test was performed after completion of the training program of both groups. 4 instruments were used for data collection. The data were analyzed using SPSS software (version 20.0). Results: The results of this study showed that students in the experimental group scored significantly higher in knowledge domain compare to control group students, and also performed better in the objective structured clinical examination (OSCE) (P<0.001). Also, this study showed that the average total score of students’ attitudes towards the role of simulators in the experimental group is higher than the control group. Statistical relationship was significant in some factors such as “patients’ safety (P= 0.014)”, “increasing the student's self-confidence (P= 0.041)”, “connecting the topics taught in the theoretical units (P= 0.024)”. Also, statistical relationship was meaningful in training with low-fidelity models which stated “it was not a reliable learning experience (P= 0.004)”.Conclusions: Simulation is an effective method for better teaching-learning that can increase knowledge, improve clinical competence, feel more confident and integrate knowledge in a safe and controlled environment.