Background & Objective: In clinical nursing education, students' attainment of self-efficacy represents the pinnacle of professional competence. This study aimed to determine the relationship between clinical instructors' leadership styles and the self-efficacy of undergraduate nursing students.

Materials and Methods: In this cross-sectional study conducted from January to February 2025, 274 undergraduate nursing students who had completed at least two semesters of clinical training were selected via convenience sampling. Data collection tools included demographic questionnaires, the Multifactor Leadership Questionnaire (MLQ), and the Nursing Profession Self-Efficacy Scale (NPSES), completed through self-report. Data were analyzed using descriptive (mean and standard deviation) and inferential statistics (independent t-test, ANOVA, Pearson correlation, and regression) in SPSS software version 26, with a significance level set at 0.05.

Results: From the students' perspective, the most and least frequently used leadership styles by clinical instructors were transactional and laissez-faire, respectively. The students' mean total self-efficacy score was 56.67 ± 18.17. Data analysis revealed a significant relationship between both transformational and transactional leadership styles and self-efficacy. Together, these two styles explained 34.1% of the variance in students' self-efficacy.

Conclusion: The findings indicate a significant relationship between clinical instructors' leadership styles and nursing students' self-efficacy. Given the central importance of self-efficacy in training competent nurses, it is suggested that targeted workshops be held to enhance clinical instructors' awareness of various leadership styles and their distinct impacts on student self-efficacy, thereby encouraging the adoption of styles that foster its development.