The Kimberley Mum’s Mood Scale (KMMS) was co-designed with Aboriginal women and healthcare professionals to improve culturally appropriate screening practices for perinatal depression and anxiety. This paper describes the implementation of the KMMS across the remote Kimberley region of Western Australia from January 2018 to December 2021. We used the Dynamic Sustainability Framework to progress the implementation and assess at the intervention, practice setting and ecological system level using a mixed methods approach to analyse implementation. Rates of administration and results of screening were described using a retrospective audit of electronic medical records. Analyses of KMMS training registry, stakeholder engagement and sustainability initiatives were descriptive. KMMS acceptability was assessed using qualitative descriptive approaches to analyse patient feedback forms (n = 39), healthcare professional surveys (n = 15) and qualitative interviews with healthcare professionals (n = 6). We found a significant increase in overall recorded perinatal screening (pre-implementation: 30.4% v Year 3: 46.5%, P < 0.001) and use of the KMMS (pre-implementation: 16.4% v Year 3: 46.4%, P < 0.001). There was improved fidelity in completing the KMMS (from 2.3% to 61.8%, P < 0.001), with 23.6% of women screened recorded as being at increased risk of depression and anxiety. Most healthcare professionals noted the high levels of perinatal mental health concerns, stress, and trauma that their patients experienced, and identified the KMMS as the most appropriate perinatal screening tool. Aboriginal women reported that it was important for clinics to ask about mood and feelings during the perinatal period, and that the KMMS was appropriate. Aboriginal women consistently reported that it was good to have someone to talk to. This study demonstrates that innovation in perinatal depression and anxiety screening for Aboriginal women is possible and can be implemented into routine clinical care with the support of a sustained multi-year investment and strong partnerships.