Background Healthcare professionals in specialist palliative care have a key role in conducting end-of-life care discussions with patients and their family caregivers. We aimed to identify key barriers and facilitators for healthcare professionals in specialist palliative care to support patients and their family caregivers in decision-making for patient end-of-life care. Methods Twenty-two healthcare professionals from different healthcare professions were recruited from a large regional specialist palliative care service in Ireland comprising 2 hospice sites. Five focus groups were conducted with participants. Data were member checked and analyzed using thematic analysis. Results Open communication and trusting relationships with patients and family caregivers combined with sufficient time for early and phased exploration of the patient’s preferences for end-of-life care, were key facilitators for participants. Family caregivers keeping information from the patient, family misunderstanding about who is responsible for decision-making, and a lack of involvement of other specialties in end-of-life care discussions were perceived by participants as key barriers. Although participants indicated they had sufficient expertise to support patients in end-of-life care decision-making, they felt that end-of-life care discussions were not solely the responsibility of specialist palliative care services. Conclusion Open communication with patients in end-of-life care decision-making can be of central importance for healthcare professionals in specialist palliative care. Further research is needed to understand the role of healthcare professionals outside of specialist palliative care in end-of-life care discussions and decision-making.