This paper illustrates how systems theory can be used in social work research design to understand the systemic issues associated with spousal care in rural Australia. Spousal caregiving is embedded within multiple formal and informal systems, including family, community, health and aged care practice, social policy, and social and cultural norms. It is therefore a complex phenomenon to explore in social research, with each of these systems interacting with and influencing other aspects of the care system. The purpose of this paper is to provide an illustration of a research design that explores this systemic complexity. The design is conceptually underpinned by the transformative paradigm; a critical approach that reflects social work principles of social justice. The methodology is based on an ecosystems approach to assessment, using multiple methods to explore interactions between systems of care at policy, practice and individual levels. This application of systems theory to research presents an innovative opportunity for social work research to reflect long-established practices of understanding complex phenomenon within its sociocultural context.