A few studies have highlighted the potential synergy between early palliative care and inclusion in an early-phase clinical trial that may improve quality of life, reduce symptoms of exhaustion related to the side effects of treatment and allow patients to complete their treatment protocol. The primary objective of this qualitative study is to evaluate the reasons for acceptance or refusal of early palliative care in patients included in early-phase clinical trials.Method and analysisAll patients from the Centre Léon Bérard (Comprehensive Cancer Centre in Lyon, France) who consent to one of the early-phase clinical trials proposed at the centre will be invited to participate in this study. The cohort will consist of a subgroup (n=20) of patients who accept palliative care together with their clinical trial, and a second subgroup (n=20) of patients who decline it. Patients will be interviewed in exploratory interviews conducted by a psychology researcher before the start of their clinical trial. The interviews will be audio-recorded. Patients will also be asked to complete quality of life and anxiety/depression questionnaires both before the beginning of the treatment and at the end of their clinical trial. The content of the interviews will be analysed thematically. Descriptive and comparative statistical analysis of both cohorts will also be conducted.Ethics and disseminationPersonal data will be collected and processed in accordance with the laws and regulations in force. All patients will give informed consent to participate. This study complies with reference methodology MR004 of the Commission Nationale de l'Informatique et des Libertés. The protocol has received the validation of an ethics committee (Groupe de Réflexion Ethique du CLB, number: 2020-006). The results will be disseminated through conference presentations and peer-reviewed publications.Trial registration numberNCT04717440.