ObjectiveThis study examines the scale of maternal mental health related contacts among Australian Aboriginal children over time, and associations with socio-economic characteristics, geographical remoteness and maternal age.DesignA retrospective cohort study of the prevalence of maternal mental health related contacts among Aboriginal children born in Western Australia between 1990 and 2013.SettingPopulation of Western Australia with de-identified linked administrative data from the Western Australian Department of Health.ParticipantsAll Aboriginal children born in Western Australia between 1990 and 2013 and their mothers.Primary outcome measurePrevalence of maternal mental health related contacts among Aboriginal children born between 1990 and 2013. Mental health related contacts were identified using mental health related inpatient hospitalisations and outpatient contacts.ResultsAlmost 30% of cohort children were born to a mother with at least one mental health contact in the 5 years prior to birth, with 15% reported in the year prior to birth and the year post birth. There was a distinct increase in the prevalence of maternal mental health contacts between 1990 and 2013 (4–5% per year, with a peak in 2007). Maternal mental health contacts were associated with living in more disadvantaged areas and major cities, and having a mother aged over 20 years at birth.ConclusionsThe study affirms that mental health issues place a considerable burden on Aboriginal Australia, and suggests that many of the mental health issues that women develop earlier in life are chronic at the time of conception, during pregnancy and at birth. Early intervention and support for women in the earliest stages of family planning are required to alleviate the burden of mental health problems at birth and after birth. There is a clear need for policies on the development of a holistic healthcare model, with a multisector approach, offering culturally appropriate services for Aboriginal people.