Backround <p>Perineal injury repair skills should be taught to students in midwifery education. One of these methods is peer-supported simulation training in simulation environments. This study aimed to determine the effect of peer-assisted episiotomy and perineal injury repair simulation on midwifery students’ anxiety and self-efficacy.</p> Methods <p>A pretest-posttest, one-group quasi-experimental design. The study was carried out with 39 third-year midwifery students studying at a foundation university. Episiotomy repair simulation was carried out peer-assisted using sponge and chicken breast. The “Introductory Information Form,” the “State-Trait Anxiety Inventory,” and the “General Self-Efficacy Scale” were used as data collection tools. In the analysis of the data, descriptive statistics and dependent group t-tests were employed to evaluate the difference between the pre-test and post-test.</p> Results <p>The mean age of the students was 21.44 ± 1.68 years (Min = 20; Max = 30). According to the results, there was a significant decrease in the mean scores of the State and Trait Anxiety scales in the pre-and post-simulation periods (Pre: State Anxiety mean 34.41 ± 9.58, Trait Anxiety 44.79 ± 9.57; Post: State Anxiety mean 30.48 ± 9.31, Trait Anxiety 41.33 ± 10.82; <i>p</i> &lt; 0.05). While no difference was observed between the pre-test and post-test in the total score of general self-efficacy (Pre: mean 62.48 ± 9.74; Post: mean 62.59 ± 11.92; <i>p</i> &gt; 0.05) of the students, there was a significant difference in the sub-dimension of Sustaining Effort &amp; Persistence (<i>p</i> &lt; 0.05).</p> Conclusions <p>The findings of this study demonstrated that peer-assisted episiotomy repair simulation training effectively reduced students’ anxiety. It is recommended that peer support be included in pre-clinical episiotomy and perineal injury repair simulation practice.</p>