Background: Family caregivers of patients on prolonged mechanical ventilation (PMV) may encounter challenges concerning medical decision-making besides witnessing patient suffering. Palliative care (PC) should be a good support for both patients and caregivers; however, for PMV families, PC is not always a choice through long companion time. This qualitative study clarifies family caregivers' burden of assisting patients on PMV and evaluates the need for PC information and support.; Methods: Interviews were caregivers of patients on ventilator support for more than 60 days in five hospitals of the Taipei City Hospital System. Based on phenomenology, this study was conducted by using a semistructured questionnaire comprising three questions: (I) what was the most crucial moment of deciding to intubate? (II) how would you describe the quality of life of your ventilator-dependent family member? (III) what type of assistance do you expect from the PC team for your ventilator-dependent family member?; Results: Twenty-one caregivers of patients on PMV in five hospitals of the Taipei City Hospital System agreed to participate in face-to-face interviews. The identified themes, including stressful decision-making, companion pain/discomfort, and unwillingness to accept PC, elucidated the difficulties experienced by caregivers when providing care.; Conclusions: Understanding family caregivers' experiences can enable physicians to improve communication with them, encourage the PC team to support them during surrogate decision-making for patients on PMV during critical moments, and enhance the overall PC service.