Objective: Increasing rates of mental health needs in child welfare clients highlight the importance of training child welfare workers in effective mental health interventions. This pilot study evaluates the effects of training public child welfare workers and interns in modularized research-supported treatments (RSTs). Methods: We compared knowledge of and attitudes toward RSTs and barriers and facilitators to their use in a sample of 26 field instructors and 11 master of social work students trained in modularized RSTs with an untrained sample of 55 field instructors and 36 students. Results: Trained field instructors had higher knowledge scores at follow-up and were more open to adopting RSTs, as compared with untrained field instructors. Fewer barriers and more facilitators were associated with more positive attitudes toward RSTs across all groups. Conclusions: Interventions to address attitudes, barriers, and facilitators may facilitate the uptake of RSTs in child welfare.