BACKGROUND: Patient- and family-centred care practices are a recommended part of contemporary care for the acutely ill hospitalized adult patients. However, how patient- and family-centred care is enacted in an adult hospital setting is not well understood. AIMS AND OBJECTIVES: The aim of this study is to explore the perceptions of patients, family members and nurses regarding family participation and collaboration in patient care within an acute care setting, including the barriers and facilitators. DESIGN: This study used a mixed-methods sequential design. METHODS: Observer-as-participant observations and semistructured interviews were undertaken. Integration of the data was achieved through triangulation. RESULTS: Triangulation revealed two metathemes. The first metatheme, 'continuum of family involvement', explained the central viewpoint of how family participation and collaboration in the care of acutely ill hospitalized adult patients was enacted. The second metatheme, 'nurses value family involvement', helped to explain and understand the barriers and facilitators to enacting family participation in the acute care setting. CONCLUSION: Promoting family participation in the acute care setting requires supporting multiple levels of engagement. Developing a relationship, clear communication and open sharing of information amongst patients, family members and nurses is critical to supporting family involvement.