This study aims to bring to light the relationship between internal/external resources and counselors’ burnout depending on the type of clients (traumatized/bereaved vs. personal growth issues). Moderated mediation analysis was conducted with 165 counselors in South Korea. The results indicated that counselors of traumatized or bereaved clients were more likely to be affected by internal resources (countertransference management ability), whereas counselors of clients with personal growth issues were more likely to be affected by external resources (environmental resources). Implications and limitations of this study are discussed.