This study aims to verify the influence of empathy of creative arts therapists on their professional development and the mediating effect of their self-reflection to this causal relationship. The survey data collected from 267 creative arts therapists were analyzed using the SPSS 25.0 program and the SPSS PROCESS macro to address the research purpose. The findings can be summarized as follows: First, the hypothesis that the empathy of creative arts therapists would affect their levels of professional development was verified. Second, the hypothesis that the self-reflection of creative arts therapists would mediate the relationship between empathy and professional development was also supported. The findings of this study imply that if a creative art therapist’s empathic ability is not high enough, self-reflection trainings can be helpful in enhancing her or his professional development. This study carries significance in that it proves important information on factors closely related to professional development of creative art therapists.