Background: Simulation continues to be an innovative teaching method that enables students to practice and gain experience. The study aimed to evaluate the effect of simulation teaching strategy on female maternity nursing students' knowledge, practices, and self-efficacy regarding breast self-examination. Method: The study's aim was accomplished using a one group pre/post-test quasi-experimental Design. Setting: The study was applied in the Faculty of Nursing, Sohag University, Egypt. Subjects: A convenient sample included 250 female students who study maternity nursing from the third year from the previously mentioned setting. Three tools were used Selfadministered questionnaire schedule, Breast self-examination observational checklist, and Students' self-efficacy (GSE) helped in collection of data. Results presented that after one month of the simulation teaching technique about breast self-examination, (96%) of the studied students had reached a satisfactory practice level. Prior to the use of the simulation teaching technique regarding breast self-examination, (70%) of the students had an unsatisfactory practice level, compared to 4% before. Conclusion Applying simulation teaching strategy regarding Breast SelfExamination help Studied students to gain more knowledge , more practice of BSE, and had better self-efficacy than before. Recommendations: To teach female maternity nursing students about breast self-examination effectively, a simulation teaching strategy should be used.