Background: Team-based and timely integrated palliative care is a gold standard of care in oncology, but issues concerning its optimal organization remain. Palliative Care in Day-Hospital (PCDH) could be one of the most efficient service model of palliative care to deliver interdisciplinary and multidimensional care addressing the complex supportive care needs of patients with advanced cancer. We hypothesize that, compared to conventional outpatient palliative care, PCDH allows the clinical benefits of palliative care to be enhanced. Methods/design: This study is a multicentre parallel group trial with stratified randomization. Patient management in PCDH will be compared to conventional outpatient palliative care. The inclusion criteria are advanced cancer patients referred to a palliative care team with an estimated life expectancy of more than 2 months and less than 1 year. The primary endpoint is health-related quality of life with deterioration-free survival based on the EORTC QLQ-C30 questionnaire. The secondary objectives are the following: increase in patient satisfaction with care using the EORTC PATSAT-C33 and OUT-PATSAT7 questionnaires, better understanding of the prognosis using the PTPQ questionnaire and advance care planning; decrease in the need for supportive care among relatives using the SCNS-P&C-F questionnaire, and reduction in end-of-life care aggressiveness. Patients will complete one to five questionnaires on a tablet before each monthly visit over 6 months and will be followed for 1 year. A qualitative study will take place, aiming to understand the specificity of palliative care management in PCDH. Cost-effectiveness, cost-utility and, an additional economic evaluation based on capability approach will be conducted from a societal point of view. Discussion: The first strength of this study is that it combines the main relevant outcomes assessing integrated palliative care; patient quality of life and satisfaction; discussion of the prognosis and advance care planning, family well-being and end-of-life care aggressiveness. The second strength of the study is that it is a mixed-method study associating a qualitative analysis of the specificity of PCDH organization, with a medical-economic study to analyse the cost of care.