Objectives: This study examines the relationship of dental hygienists' professional self-concept, self-leadership, job stress, and fatigue with their clinical competence in order to identify factors that can improve clinical competence. This study is intended to provide basic information to develop educational programs for dental hygienist's clinical competence. Methods: The self-administered questionnaire survey was conducted with 243 dental hygienists working at dental clinics in Gwangju and Jeonnam from August 14, 2017 to September 9, 2017. The data regarding the general characteristics, professional self-concept, self-leadership, job stress and fatigue, and clinical competence were collected, and analyzed through independent t-tests, one-way analysis of variance (ANOVA), Pearson's correlation coefficient, and multiple regression analysis using the SPSS Windows ver. 22.0. Results: High professional self-concept (r=0.54) and self-leadership(r=0.48) were associated with high clinical competence. High self-leadership (r=0.53) was associated with high professional selfconcept. High fatigue(r=-0.21) was associated with low professional self-concept(P<0.01). The highest factor influencing clinical competence was professional self-concept, followed by selfleadership, total clinical experience, education level, and fatigue (P<0.05). Conclusions: Based on the findings, it is necessary to develop educational programs which can improve autonomy and develop professionalism to enhance clinical competence in consideration of work experience and educational levels in dental hygienists.