Background <p>Approximately half of all adverse events occur in the operating room, highlighting the critical role of non-technical skills in operating rooms. Effective non-technical skills among operating room nurses can significantly reduce the occurrence of such events. Moreover, self-efficacy in non-technical skills may directly impact professional performance and patient safety. Therefore, this study aimed to investigate the impact of intraoperative non-technical skills training on scrub practitioners' self-efficacy.</p> Methods <p>In a randomized controlled trial, 30 scrub practitioners were assigned to the intervention group and 30 to the control group through random allocation. The intervention group underwent training in non-technical skills using a combined technique of lectures and simulated video scenarios delivered in two two-hour training sessions. Meanwhile, the control group received no training. The data collection tool was a two-part questionnaire. The first part collected demographic data (age, gender, work experience, and educational level), while the second part assessed scrub practitioners' self-efficacy in intraoperative non-technical skills. The questionnaire was administered online in two phases, with a one-month interval between them, through the Telegram application to the participants in both groups. The data were analyzed using descriptive statistics, independent t-tests, and paired t-tests.</p> Results <p>The demographic variables of the intervention group did not show significant differences compared to the control group. The independent t-test revealed no significant difference in overall self-efficacy between the intervention and control groups before the training (<i>P</i> = 0.513). However, after the training, a statistically significant difference was observed (<i>P</i> = 0.025). There were no significant differences among the self-efficacy components between the intervention and control groups before the training (<i>P</i> &gt; 0.05). However, after the training, self-efficacy in the two skills of situation awareness and communication and teamwork showed statistically significant differences (<i>P</i> &lt; 0.05).</p> Conclusion <p>Non-technical skills are crucial for scrub practitioners to perform their tasks safely and efficiently. Training can enhance the self-efficacy of scrub practitioners in their non-technical skills. Therefore, it is necessary to incorporate non-technical skills training into the educational curriculum and continuing education programs for scrub practitioners.</p> Trial registration <p>The IRCT code (IRCT20150715023216N15) was obtained from the Iranian Clinical Trials Registry website on 2023/08/05 before sampling.</p>