This document from the Institut Montaigne outlines the immense potential of health data and its secondary uses to improve healthcare services, research, and policy. It highlights the importance of better utilizing health data to accelerate research, enhance early detection, aid in diagnostics, improve predictive health, and personalize patient care. Despite France’s pioneering efforts with the National Health Data System (SNDS), challenges remain in terms of data interoperability, economic valuation, and legal frameworks. The document presents several key recommendations to overcome these obstacles and optimize the use of health data for innovation and better health outcomes.