Objectives: Family caregivers of patients requiring prolonged mechanical ventilation may experience physical and psychological morbidity associated with a protracted intensive care unit experience. Our aim was to explore potentially modifiable support needs and care processes of importance to family caregivers of patients requiring prolonged mechanical ventilation and transition from the intensive care unit to a specialised weaning centre. Research methodology/design: A longitudinal qualitative descriptive interview study. Data was analysed using directed content analysis. Setting: A 6-bed specialised weaning centre in Toronto, Canada. Findings: Eighteen family caregivers completed interviews at weaning centre admission (100%), and at two-weeks (40%) and three-months after discharge (22%) contributing 29 interviews. Caregivers were primarily women (61%) and spouses (50%). Caregivers perceived inadequate informational, emotional, training, and appraisal support by health care providers limiting understanding of prolonged ventilation, participation in care and decision-making, and readiness for weaning centre transition. Participants reported long-term physical and psychological health changes including alterations to sleep, energy, nutrition and body weight. Conclusions: Deficits in informational, emotional, training, and appraisal support of family caregivers of prolonged mechanical ventilation patients may increase caregiver burden and contribute to poor health outcomes. Strategies for providing support and maintaining family caregiver health-related quality of life are needed.