Background: Simulation is a good fit in a practice profession such as nursing. It provides virtual clinical experiences and environments rich in diversity and exposure, yet safe for experimentation and learning for mental health nursing students.Aim of the study : the aim of this study was to evaluate the effect of simulation on nursing Students' academic motivation and perceived learning in psychiatric nursing. Setting: The study was conducted at the Faculty of Nursing - Tanta University that is affiliated to the Ministry of Higher Education. Subjects:The study subjects were composed of all nursing students (250 students), enrolled in the psychiatric nursing course, during the first and second semester of the fourth academic year (2020-2021) at faculty of Nursing -Tanta University. The students were divided into two main groups; experimental group (150 students) and control group (100 students). Design a quasiexperimental design was utilized. Tools: three tools were used; perceived learning scale, a manual of academic motivation questionnaire, and simulation evaluation questionnaire. Results: there was a statistical significant improvement in the nursing student‟s academic motivation and perceived learning in the experimental group after simulation based learning program. Conclusion: clinical simulation has a salient effect on improving the students‟ academic motivation and perceived learning in psychiatric nursing. Recommendation: Variables such as students' online class interaction, their motivation to participate in the online class, course structure, and instructor facilitation and knowledge are important determinants of perceived student learning and motivation