France has centralized national medical-social and economic databases, established and managed by public agencies, that provide comprehensive and ongoing coverage of the entire population across various areas critical to public health and research: healthcare utilization, hospitalizations, disabilities, benefits, and occupational, social, and economic status. Furthermore, a unique individual identifier (the NIR: Registry Identification Number) is currently used by virtually all national databases. Despite certain limitations in terms of coverage, data quality, and validity, these databases, covering more than 60 million people, constitute a considerable resource, likely unmatched anywhere in the world. However, the use of these national databases for research and surveillance purposes currently faces various obstacles, the most significant of which are of a legal and operational nature. In response to a request from the DGS, this document reviews the main existing databases, outlines the difficulties in using them, and presents in detail a series of proposals to overcome them. (R.A.)