Context: A broad range of knowledge, skills, and abilities related to leadership has been suggested as essential for development during the athletic training education process. Though the importance of these characteristics has been established, researchers have not yet evaluated the self-perceived proficiency levels of new-to-practice athletic trainers (ATs). Objective: To determine the level of self-perceived proficiency attained on key leadership competencies by new-to-practice ATs and to determine which factors relate to increased levels of self-perceived proficiency. Design: Quantitative survey research. Setting: Online questionnaire. Patients or Other Participants: One hundred seventy-three ATs within their first 5 years of practice participated in the study. Main Outcome Measure(s): Participants completed a Web-based questionnaire developed by the researchers to determine the self-perceived level of proficiency attained by the new-to-practice AT on 5 key leadership competencies. One open-ended response item allowed participants to suggest educational experience changes that could lead to increased proficiency in the 5 key leadership competencies. Results: Athletic trainers who completed their professional education at the master's level selected higher self-perceived proficiency levels for the competency "knowledgeable" than those who completed bachelor's degrees to complete their professional athletic training requirements. As years of practice increased, ATs perceived higher levels of proficiency in the competencies of "knowledgeable," "ethical practice," and "credible." Level of self-perceived proficiency ratings for "adaptable and resilient" were significantly lower than those for other competencies, regardless of demographic variables. Conclusions: Completion of professional education at the master's degree level resulted in increased self-perceived levels of knowledge in new-to-practice ATs. Self-perceived proficiency in the characteristic of adaptability and resilience lags behind other key competencies even as years of practice increase. Instructors could use pedagogical and curricular strategies from other health care professions to increase adaptability and resilience in athletic training students.