<p>This study examined the variables of career locus of control and career decision-making self-efficacy, which are thought to be related to career indecision experienced by adolescents. In this context, a model was proposed in which the mediating role of career decision-making self-efficacy in the relationship between internal and external career locus of control and career indecision was tested. The participants of the study consisted of 365 (261 female, 104 male) students in the 9-10-11-12th grades of high school. The average age of the participants was 16.21 years. The Career Decision Inventory, Career Decision-Making Self-Efficacy Scale-Short Form and Career Locus of Control scales were used to collect data within the scope of the study. The findings of the study reveal that there is a significant negative relationship between career indecision and career decision-making self-efficacy and internal career locus of control and a significant positive relationship with external career locus of control. Analyses of the mediating role of career decision-making self-efficacy revealed that it mediated the relationship between internal career locus of control and career indecision, whereas external career locus of control did not mediate the relationship between career indecision and career decision-making self-efficacy.</p>