Aim and objectives: To explore the underlying theoretical framework for the role adaptation of family caregivers for ventilator-dependent patients after transferring from respiratory care ward to home. Background: The number of ventilator-dependent patients has been increasing worldwide. Under Taiwan's National Health Insurance policy, if ventilator-dependent patients are stable, they should be transferred from an acute care hospital to a subacute unit or home. Design: A qualitative design based on grounded theory was adopted for this study. Methods: One-on-one, in-depth interviews were conducted with a purposive sample of 15 family caregivers who were caretaking ventilator-dependent patients at their home two months after hospital discharge. Theoretical sampling was used until concepts emerging in data analysis were saturated. Analysis of audio-taped interview transcripts generated a process of role adaptation for family caregivers of a ventilator-dependent patient. Results: The caregiver's transition to the care-giving role is a dynamic process with consequences that are impacted by level of support from the family, affective rewards from the patient, patient's health condition and a balanced life schedule for the caregiver. Conclusions: The results of this study can provide respiratory care professionals with skills to assess the needs of caregivers for ventilator-dependent patients and individualise interventions to caregivers' specific needs. Relevance to clinical practice: The findings of this study contribute to nurses' understanding and promotion of role adaptation for family caregivers among ventilator-dependent patients.