The Australian Therapy Outcome Measure for Indigenous Clients (ATOMIC) is a goal-setting tool designed to measure therapy outcomes with First Australians. It was originally developed and validated for use with First Australian children as a culturally responsive alternative to traditional western outcome measures. This research explored the applicability, responsiveness and clinical utility of the ATOMIC when used with First Australian adults attending an urban health service. Separate parallel studies investigated responsiveness and clinical utility. The first employed quantitative methods to investigate change over time via pre- and post-intervention data. The second employed a qualitative phenomenological approach to determine the clinical utility of the tool. Semi-structured interviews and focus groups were used, respectively, to understand the experience of using the ATOMIC from a client and clinician perspective. Client perspectives on the purpose of the tool and its alignment with their views on health care and therapists' perspective on the ease of use and applicability of the tool to the health service setting were explored. These data were analysed using reflexive thematic analysis. The methodological approach followed National Health and Medical Research Council (NHMRC, 2018) guidelines in considering cultural continuity, reciprocity and equity. This project was initiated and guided by Aboriginal and Torres Strait Islander leaders (the advisory group) as a prioritised need for a robust way of reporting outcomes to complement existing statistical and narrative data within a large community-controlled health service. The advisory group provided high level governance from project conception to conclusion and were involved in yarn-backs about research findings. Responsiveness: Wilcoxon test showed a statistically significant increase (P = 0.00) in ATOMIC scores pre- (mean = 1.8) and post- (mean = 8) intervention. Effect size (Cohen d) was deemed significant calculated at 2.1. Findings included: First Australian clients are adept at self-managing their conditions; the ATOMIC is a clinically useful outcome measure, which reflects this; ATOMIC is an acceptable tool to First Australian clients and clinicians and supports culturally responsive goal setting and occupational therapy practice. The Australian Therapy Outcome Measure for Indigenous Clients (ATOMIC) was created to measure how well therapy works for First Australian children. This research investigates whether it also works with adult First Australians. Two studies were undertaken: a quantitative study to see whether ATOMIC scores changed before and after therapy and a qualitative study, which asked people what they thought about using the ATOMIC. ATOMIC scores went up after therapy, indicating it is sensitive to change, and both clients and therapists liked using the ATOMIC and found it useful. It matched well with how First Australian adults see health care and helped set goals for therapy. The results of the study show that the ATOMIC is helpful for both clients and therapists in understanding how well therapy works and helps to set goals that make sense culturally. This study looked at one health service in one regional area, so more research is needed to establish whether it works elsewhere. Overall, the results indicate the ATOMIC is a promising step towards better therapy for Indigenous Australians.