There is a paucity of research exploring Indigenous women's experiences in acute mental health inpatient services in Australia. Even less is known of Indigenous women's experience of seclusion events, as published data are rarely disaggregated by both indigeneity and gender. This research used secondary analysis of pre-existing datasets to identify any quantifiable difference in recorded experience between Indigenous and non-Indigenous women, and between Indigenous women and Indigenous men in an acute mental health inpatient unit. Standard separation data of age, length of stay, legal status, and discharge diagnosis were analysed, as were seclusion register data of age, seclusion grounds, and number of seclusion events. Descriptive statistics were used to summarize the data, and where warranted, inferential statistical methods used SPSS software to apply analysis of variance/multivariate analysis of variance testing. The results showed evidence that secondary analysis of existing datasets can provide a rich source of information to describe the experience of target groups, and to guide service planning and delivery of individualized, culturally-secure mental health care at a local level. The results are discussed, service and policy development implications are explored, and suggestions for further research are offered. © 2016 Australian College of Mental Health Nurses Inc.