The purpose of this research was to address the need for evidence-based practice in child care and protection settings by evaluating the feasibility and effectiveness of two therapeutic interventions (Trauma-Focussed Cognitive Behavioural Therapy [TFCBT] and a sensory intervention [SI]), and developing a combined intervention (Sensory and Trauma Focussed Cognitive Behavioural Therapy [STF-CBT]) for the treatment of maltreated children diagnosed with post-traumatic stress disorder (PTSD). While TF-CBT has been well researched internationally for child maltreatment trauma, New Zealand research was sparse and dated. More recently developed sensory approaches have shown promise as an alternative or additional intervention; however, a systematic literature review, carried out as part of the current research, found that empirical research for the use of sensory approaches for child trauma was lacking (Study 1). A quasi-experimental multiple baseline single case design was employed to evaluate the feasibility and effectiveness of existing TF-CBT and a newly adapted SI with maltreated children referred for therapy within New Zealand’s statutory child protection agency (Study 2 and 3). Participants comprised children aged 9-11 years (n=7) who met diagnostic criteria for PTSD. Outcomes were assessed using visual analysis of single-case data, comparison of pre- and post-intervention comorbid functioning measures, and supplemented with additional subjective data collected from participants and therapists. Despite some methodological difficulties related to the complexity of the population, both TF-CBT and the SI demonstrated positive outcomes for children exposed to trauma and multiple maltreatment. For both TF-CBT and SI, all participants demonstrated increased self-perceived ability to cope with distressing situations, decreased PTSD symptoms, and decreased comorbid depression symptoms postintervention. All TF-CBT participants demonstrated decreased self-reported anxiety at post assessment, but both participants receiving the SI reported increased anxiety at post-assessment. Subjective data from all participants suggested they valued learning skills to cope with their trauma symptoms, and TF-CBT participants appreciated having the opportunity to process their trauma using sandplay and art. Results highlighted the importance of trauma processing, as well as a need to build on the relational and selfregulation aspects of the approaches, thus providing rationale for the combined sensory and TF-CBT model (Sensory and Trauma Focused CBT; STF-CBT). Development of the STF-CBT intervention and preliminary feedback from clinicans comprised Study 4. STF-CBT is designed to provide children with a greater understanding of sensory reactions to trauma, provide skills for self-regulation and coping, and allowing processing of their traumatic experiences in a safe therapeutic environment. STF-CBT, therefore, has potential as an acceptable intervention for treating multiply maltreated children. Further research is recommended. This research identified that the context in which children receive treatment impacts outcomes. For instance, participants experienced ongoing distress, unsafe environments, and instability. These experiences limited participants’ ability to attend therapy sessions, build a trusting relationship with the therapist, engage in session activities, and make positive progress. Therefore, it is important to develop and evaluate effective interventions for treating trauma with recognition that therapy is just one part of the picture, and maltreated children require a multi-faceted approach to enhancing their mental health, safety, and wellbeing.