Introduction:The Chronic Disease Self-Management Programme (CDSMP) has resulted in improved health outcomes for patients. However, research has focused mainly on those with chronic conditions and has not extensively explored prevention programmes targeting individuals with specific vulnerability profiles.Aim: This study aimed to understand the effects of the CDSMP on the lived experience of vulnerable patients included in the EFFICHRONIC project in France, based on their needs and expectations before and after participation.Methods: We conducted a qualitative phenomenological semio-pragmatic study based on 37 in-depth interviews with 20 patients (20 before/17 after CDSMP).Results: By transforming existential dimensions (identity, relationship with others and bodily experience), chronic illness generates new needs in the vulnerable person.By resonating with the expectations and needs of participants, the CDSMP induces motivation and a sense of belonging to a community of peers. It has enabled the participants to become actors of their own health until empowerment. Although some limitations are reported, the programme has awakened a desire in the participants to take better care of their health and to develop personal skills with, for some, a desire to become involved in health education. Conclusion:Our phenomenological approach highlighted the resonance between the programme (its design and implementation) and the lived experience of patients, as an effective element of empowerment. This necessitates training the facilitators to elicit the lived experience of patients. Furthermore, as a patient-centred approach is required, the facilitators need to learn how to adapt the design of the programme to the singularity of the patient.