Background. In Canadian baccalaureate nursing education, many schools pair their nursing students with a nurse preceptor to complete a consolidation placement in their final year of studies. The preceptor plays an important role in students’ learning and their success in the program. Although there are many factors that may influence preceptors’ ability to be successful in the role, the literature suggests that self-efficacy may affect their performance as a preceptors and may have an impact on students’ learning and their preceptorship experience. Self-efficacy is defined as a person’s confidence in their abilities to complete a task or goal. As such, preceptors with greater self-efficacy may be more effective in their role and may have a positive impact on students’ learning. Therefore, it is important to assess factors that influence preceptors’ self-efficacy as this knowledge could help inform and target the development of preceptor training programs, preceptor selection criteria and preceptor supports. Objectives. The purpose of this thesis is to explore the factors that affect the self-efficacy of preceptors. Five factors were investigated, including: (1) nursing experience, (2) preceptor experience, (3) vicarious preceptor experience, (4) preceptor training, and (5) the personality trait neuroticism. These variables are derived from Bandura’s (1986) theory of self-efficacy. Design. This study was conducted using a cross-sectional, non-experimental study design. Methods. A total of 95 nurse preceptors participated in the study by completing an online survey and were recruited using multiple strategies, including social media. The survey was comprised of demographic questions, a measure of the Big-Five personality traits, and a measure of clinical teaching self-efficacy. Correlation, independent t-tests and ANOVAs were done to analyze the data. Results. A statistically significant correlation was found between self-efficacy and two independent variables: nursing experience (r = 0.33, p < 0.01) and the personality trait of neuroticism (r = -0.21, p = .05). Additionally, self-efficacy was correlated with agreeableness (r = 0.22, p = .03) and age (r = 0.41, p < 0.01). A statistically significant difference in self-efficacy was found between diploma and bachelor degree nurses (mean difference = 0.37, p = .02), and bachelor degree and graduate degree nurses (mean difference = -0.45, p = .02). Conclusion. Three key results were found to influence the self-efficacy of nurse preceptors. This knowledge can be incorporated into preceptor training, preceptor support and the preceptor selection process.