Introduction: The challenges of global aging and the growing burden of chronic diseases require innovative interventions on health determinants such as social participation. However, many older adults do not have equitable opportunities to achieve full social participation, and existing interventions under-empower personal and environmental resources and reach a minority. To optimize current practices, a new intervention operating in complemetarity with existing resources, the APIC, demonstrated feasibility and first indications of positive impacts, but needs further evaluation. Methods and analysis: A pragmatic multicentre, prospective, two-armed, randomized controlled trial will evaluate the impacts and cost-effectiveness of the APIC on older adults' health, social participation and life satisfaction. A total of 376 participants restricted in at least one instrumental activity of daily living and living in one of the three large cities of Quebec, Canada, will be randomly assigned to the experimental or control group using a centralised computer-generated random number sequence procedure. The experimental group will receive weekly 3-hour personalized stimulation sessions over a 12-month period by a specially trained volunteer. Sessions will encourage empowerment, gradual mobilization of personal and environmental resources, and community integration. The control group will receive the usual publicly-funded universal health services available to all Quebecers. Self-rated questionnaires will assess over a 2-year period the physical and mental health [primary outcome; v2 of the 36-Item Short-Form Health Survey, converted to SF-6D utility scores for quality-adjusted life years (QALY) calculation], social participation (Social Participation Scale) and life satisfaction (Life Satisfaction Index-Z). The use of healthcare services will also be recorded and costs of each intervention will be considered. Ethics and dissemination: The Research Ethics Committee of the CIUSSS Estrie- CHUS will approved the study (#). All participants will sign an informed consent form. At the end of the study, participants of the control group will be offered APIC. Findings will be published in peer-reviewed journals and presented at local, national and international conferences.Trail registration number: NCT (#)