Introduction & Objective: The concept of self-efficacy stems from social-cognitive theory. Present research was conducted, consistent with Bandura’s Self-Efficacy Theory, with the purpose of identified correlation of nursing students’ self-efficacy with clinical performance.Materials & Methods: This correlation study conducted with a sample of 207 nursing students. The research instruments concluded, “Clinical Performance Self-efficacy” scale consists of four dimensions with 37 items (0-100 Likert-format) and “Nursing Clinical Performance” with 5 case scenario and 15 questions. Validity and reliability of the scales were tested. Internal reliability of “Clinical Performance Self-efficacy” scale had α=0.96; the dimensions Cronbach’s a ranged from 0.90 to 0.92. Test–retest reliability with a 2-week time interval was r=0.94. Internal reliability of “Nursing Clinical Performance” scale had a=0.78. Test–retest reliability was r=0.81.Results: Result showed that significant correlation was detected between "clinical performance self-efficacy" and "nursing clinical performance" (r=0.425, p<0.001).Conclusion: Based of the percentile average of scores, self-efficacy and clinical performance of nursing students were moderate.Also, there was significant correlation between "clinical performance self-efficacy" and "nursing clinical performance" of nursing students. Therefore, non educational factors, such as self-efficacy, had an important role in students' performances, especially in clinical settings.