This study attempted to grasp to what extent Korean art therapists perceive the importance of their competency factors and how much they are implementing them in actual scenes. Based on this, the study’s purpose was to diagnose art therapists insufficient competency factors and to present an objective basis for preparing practical alternatives to improve them. For 102 art therapists working in the field, the importance-performance analysis (IPA) was conducted regarding their perceived competency. As a result, when comparing the perception of importance and execution degree of art therapists’ knowledge competency, all 14 competency factors showed significant differences. Next, when comparing the difference between the importance and execution degrees of therapists’ skill competency, all eight competency factors showed significant differences. Lastly, as a result of comparing the difference between the importance and performance of attitude and individual competency group, all eight factors showed a significant difference in the importance and execution of the art therapist. This study investigated the perception of the competence of art therapists working in art therapy fields, and discussed limitations and suggestions for future research. The results of this study are expected to serve as the basis for preparing measures that improve the overall professionalism of Korean art therapists.