Children in the United States are experiencing a mental health crisis characterized by diagnoses of serious mental health disorders (CDC, 2013; SAMHSA, 2012; U.S. Public Health Service, 2000). One component of the array of treatment approaches for child mental health issues is residential treatment in which children receive therapeutic services in a residential setting. Children in residential treatment have experienced a variety of issues by the time they come into treatment, including: one or more mental health diagnoses (Connor, Doerfler, Toscano, Volungis, & Steingard, 2004; Handwerk et al., 2006; Sternberg et al., 2013), a history of abuse (Bettman, Lundahl, Wright, Jasperson, & McRoberts, 2011; Connor et al., 2004), and high rates of externalizing behaviors (Bettman et al., 2011; Connor et al., 2004; Handwerk et al., 2006; Sternberg et al., 2013; Trout et al., 2008). In a residential care setting, the primary source of direct resident care is residential care workers (RCW), who are prone to burnout (Seti, 2008) and must find ways to build relationships with the children in their care, as those relationships are important to the success of treatment (Moses, 2000). One promising approach to address this relational need is Child Teacher Relationship Training (CTRT; Morrison, 2006), which shows promise in addressing both teacher perceptions of children's behavior (e.g., Morrison, 2006) and teachers' relationships with children (e.g., Sepulveda, Garza, & Morrison, 2011). This study used a mixed methods approach consisting of a primary single-case experimental design with a qualitative case study to investigate the effects of CTRT in the residential treatment environment with RCWs. More specifically, the study investigated effects of CTRT on RCWs': (a) perceptions of children's behaviors, (b) relationship with the child of focus, (c) ability to demonstrate empathy in individual play sessions, (d) ability to generalize child-centered play therapy skills to a classroom/group environment, and (e) symptoms of burnout. Additionally, the study qualitatively explored the RCWs' challenges, experiences, and perceptions related to the CTRT. Qualitative data suggested that the participants experienced the training positively and found it useful, experienced some challenges with the training, and planned to keep using the skills. The percentage of data points exceeding the median (PEM; Ma, 2006) was calculated and indicated that participants were able to generalize child-centered play therapy skills to their classroom. The treatment effects ranged from mildly effective to very effective (Scruggs & Mastropieri, 1998). The percentage of non-overlapping data (PND; Scruggs, Mastropieri, & Casto, 1987) was calculated and indicated that the treatment was very effective in helping participants increase the demonstration of empathy in play sessions. Qualitative descriptions of the relationship between the RCWs and their COFs were positive, but the quantitative data did not consistently align with the qualitative data across all participants. Two participants described ongoing experiences of behavioral challenges with their COF and one did not, which was supported by the quantitative data related to COFs' behavioral problems. Symptoms of burnout did not improve, but participants described job-related improvements related to the training.