Children in the United States are experiencing a mental health crisis (Centers for Disease Control & Prevention, 2013; 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 including disruptions in attachment (Walter, 2007). However, relationships are important to the success of treatment (e.g., Ayotte, Lanctôt, & Tourigny, 2016; Gallagher & Green, 2012). One promising approach to address this relational need is child-parent relationship therapy (CPRT; Landreth & Bratton, 2019). To investigate the effects of CPRT with residential care workers (RCWs), this study used a mixed-methods approach including a single-case experimental design and a qualitative case. More specifically, the study investigated effects of CPRT on RCWs’ (a) perceptions of children’s behaviors, (b) relationships with the children of focus, and (c) ability to demonstrate empathy in individual play sessions. The percentage of nonoverlapping data (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 children of focus (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.