Background: Outcome measurement plays an increasing role in improving the quality, effectiveness, efficiency and availability of palliative care. Aim: To provide expert recommendations on outcome measurement in palliative care in clinical practice and research. Methods: Developed by a European Association for Palliative Care Task Force, based on literature searches, international expert workshop, development of outcome measurement guidance and international online survey. A subgroup drafted a first version and circulated it twice to the task force. The preliminary final version was circulated to wider expert panel and 28 international experts across 20 European Association for Palliative Care member associations and the European Association for Palliative Care Board of Directors and revised according to their feedback. The final version was approved by the European Association for Palliative Care Board for adoption as an official European Association for Palliative Care position paper. Results: In all, 12 recommendations are proposed covering key parameters of measures, adequate measures for the task, introduction of outcome measurement into practice, and national and international outcome comparisons and benchmarking. Compared to other recommendations, the White Paper covers similar aspects but focuses more on outcome measurement in clinical care and the wider policy impact of implementing outcome measurement in clinical palliative care. Patient-reported outcome measure feedback improves awareness of unmet need and allows professionals to act to address patients' needs. However, barriers and facilitators have been identified when implementing outcome measurement in clinical care that should be addressed. Conclusion: The White Paper recommends the introduction of outcome measurement into practice and outcomes that allow for national and international comparisons. Outcome measurement is key to understanding different models of care across countries and, ultimately, patient outcome having controlled for differing patients characteristics.