Chronic diseases and their associated biopsychosocial adjustements tax the limits of modern conventional medicine, with the need then to turn towards new resources. Among these, Mindfulness-Based Stress Reduction (MBSR) is a therapeutic approach developed more than 30 years ago. Designed as an adjuvant to medical care, in particular in the case of chronic pain which is the scope of our article, MBSR is usually provided in group format and based on a meditative practice. Simple, brief and cost-limited, MBSR can potentially be offered to a wide variety of chronic diseases and is part of participatory medicine. After having presented this approach, several results from studies confirming the legitimacy of MBSR as a nonreligious and nonesoteric scientific approach for the treatment of various diseases will be reported.