The benefits of palliative care rely on how healthcare professionals assess patients' needs in the initial encounter/s; crucial to the design of a personalised therapeutic plan. However, there is currently no evidence-based guideline to perform this needs assessment. We aim to design and evaluate a proactive and systematic method for the needs assessment using quality guidelines for developing complex interventions. This will involve patients, their relatives and healthcare professionals in all phases of the study and its communication to offer clinical practice a reliable approach to address the palliative needs of patients. To design and assess the feasibility of an evidence-based, proactive and systematic Multidimensional needs Assessment in Palliative care (MAP) as a semistructured clinical interview guide for initial palliative care encounter/s in patients with advanced cancer. This is a two-phase multisite project conducted over 36 months between May 2019 and May 2022. Phase I includes a systematic review, discussions with stakeholders and Delphi consensus. The evidence gathered from phase I will be the basis for the initial versions of the MAP, then submitted to Delphi consensus to develop a preliminary guide of the MAP for the training of clinicians in the feasibility phase. Phase II is a mixed-methods multicenter feasibility study that will assess the MAP's acceptability, participation, practicality, adaptation and implementation. A nested qualitative study will purposively sample a subset of participants to add preliminary clues about the benefits and barriers of the MAP. The evidence gathered from phase II will build a MAP user guide and educational programme for use in clinical practice. Ethical approval for this study has been granted by the university research ethics committee where the study will be carried out (approval reference MED-2018-10). Dissemination will be informed by the results obtained and communication will occur throughout.