Background: Several studies have highlighted the need for improvement in palliative care delivered to older people long-term care facilities. However, the available evidence on how to improve palliative care in these settings is weak, especially in Europe. We describe the protocol of the PACE trial aimed to 1) evaluate the effectiveness and cost-effectiveness of the 'PACE Steps to Success' palliative care intervention for older people in long-term care facilities, and 2) assess the implementation process and identify facilitators and barriers for implementation in different countries. Methods: We will conduct a multi-facility cluster randomised controlled trial in Belgium, Finland, Italy, the Netherlands, Poland, Switzerland and England. In total, 72 facilities will be randomized to receive the 'Pace Steps to Success intervention' or to 'care as usual'. Primary outcome at resident level: quality of dying (CAD-EOLD); and at staff level: staff knowledge of palliative care (Palliative Care Survey). Secondary outcomes: resident's quality of end-of-life care, staff self-efficacy, self-perceived educational needs, and opinions on palliative care. Economic outcomes: direct costs and quality-adjusted life years (QALYs). Measurements are performed at baseline and after the intervention. For the resident-level outcomes, facilities report all deaths of residents in and outside the facilities over a previous four-month period and structured questionnaires are sent to (1) the administrator, (2) staff member most involved in care (3) treating general practitioner, and (4) a relative. For the staff-level outcomes, all staff who are working in the facilities are asked to complete a structured questionnaire. A process evaluation will run alongside the effectiveness evaluation in the intervention group using the RE-AIM framework. Discussion: The lack of high quality trials in palliative care has been recognized throughout the field of palliative care research. This cross-national cluster RCT designed to evaluate the impact of the palliative care intervention for long-term care facilities 'PACE Steps to Success' in seven countries, will provide important evidence concerning the effectiveness as well as the preconditions for optimal implementation of palliative care in nursing homes, and this within different health care systems. Trial registration: The study is registered at www.isrctn.com - ISRCTN14741671 (FP7-HEALTH-2013-INNOVATION-1 603111) Registration date: July 30, 2015.