On behalf of the group responsible for the management, surveillance, and investigation of SARS, the author presents the national epidemiological surveillance system for SARS cases: case identification, case classification, and contact tracing. The data presented reflect the situation in France as of May 27, 2003: of the 426 possible cases reported by clinicians, 7 were considered probable cases; these 7 probable cases were linked to 2 clusters (one associated with the French Hospital in Hanoi, the other involving a professional team returning from China).