Objectives: Research on the needs of family caregivers of people living with cancer remains disproportionately focused in high income contexts. This research gap adds to the critical challenge on global equitable delivery of cancer care. This study describes the roles of family caregivers of people living with cancer in Vietnam and possible implications for intervention development. Methods: Semi‐structured interviews and focus groups with family caregivers (n = 20) and health care providers (n = 22) were conducted in two national oncology hospitals. Findings were verified via workshops with carers (n = 11) and health care professionals (n = 28) in five oncology hospitals representing different regions of Vietnam. Data was analyzed collaboratively by an international team of researchers according to thematic analysis. Results: Family caregivers in Vietnam provide an integral role in the delivery of inpatient cancer care. In the hospital environment families are responsible for multiple roles including feeding, hydration, changing, washing, moving, wound care and security of personal belongings. Central to this role is primary decision making in terms of treatment and end‐of‐life care; relaying information, providing nutritional, emotional and financial support. Families are forced to manage severe complications and health care needs with minimal health literacy and limited health care professional input. Conclusions: Understanding context and the unique roles of family caregivers of people living with cancer is critical in the development of supportive services. As psycho‐oncology develops in low and middle income contexts, it is essential that family caregiver roles are of significant importance.