Stakeholders are people with an interest in a topic. Internationally, stakeholder involvement in palliative care research and health technology assessment requires development. Stakeholder involvement adds value throughout research (from prioritising topics to disseminating findings). Philosophies and understandings about the best ways to involve stakeholders in research differ internationally. Stakeholder involvement took place in seven countries (England, Germany, Italy, Lithuania, the Netherlands, Norway and Poland). Findings informed a project that developed concepts and methods for health technology assessment and applied these to evaluate models of palliative care service delivery. To report on stakeholder involvement in the INTEGRATE-HTA project and how issues identified informed project development. Using stakeholder consultation or a qualitative research design, as appropriate locally, stakeholders in seven countries acted as 'advisors' to aid researchers' decision making. Thematic analysis was used to identify key issues across countries. A total of 132 stakeholders (82 professionals and 50 'lay' people) aged ⩾18 participated in individual face-to-face or telephone interviews, consultation meetings or focus groups. Different stakeholder involvement methods were used successfully to identify key issues in palliative care. A total of 23 issues common to three or more countries informed decisions about the intervention and comparator of interest, sub questions and specific assessments within the health technology assessment. Stakeholders, including patients and families undergoing palliative care, can inform project decision making using various involvement methods according to the local context. Researchers should consider local understandings about stakeholder involvement as views of appropriate and feasible methods vary. Methods for stakeholder involvement, especially consultation, need further development.