A social experiment and pilot project funded by the French Directorate General of Social Cohesion aimed at providing legal aid services ("legal empowerment and mental health") has been conducted since 2009 in three healthcare institutions in Paris (France): the Centre Hospitalier Sainte-Anne, the Groupe Public de Santé Perray-Vaucluse, and the Hôpital Tenon (psychotraumatology unit). Lasting until 2012 and piloted by the NGO Droits d'Urgence, the initiative aims to promote the legal empowerment of socially excluded people suffering from psychiatric or mental disorders and to facilitate access to care. The initiative operates on two levels, providing legal support to vulnerable people and offering legal expertise and advice to medical and social staff. An ad-hoc intervention approach was designed to ensure the implementation of the initiative based on several combined tools: legal aid, technical committees, awareness-raising activities, and pooling of legal resources and information. Developed across the three institutions, this integrated and subsidiary initiative improves our understanding of the complex circumstances of disempowered people ? who are often faced with overlapping social, medical, administrative and legal difficulties ? and helps to take into account their vulnerabilities. The cross-professional and cross-boundary system promoted by this initiative involves medical staff, social workers and lawyers around patients viewed as both actors and legal subjects.