In August 2004, 15 cases of tularemia occurred following a visit to a mill in the Vendée region. A site visit to the mill and three studies—descriptive, retrospective cohort, and environmental—were conducted. The 39 people present at the mill between July 24 and August 11 were interviewed about their symptoms and exposures (food, animals, leisure activities). A case was defined as fever and positive serology: seroconversion or a significant increase in antibody titer, or a single titer of 40 or higher. F. tularensis was tested for by culture and PCR in the water supply, firewood, and domestic animals at the mill. Fifteen patients (38%) were identified, 12 (80%) of whom had the pulmonary form. None were hospitalized. Attendance at the mill for the dinner on August 4 was strongly associated with the disease (p<10⁻⁸). One of the three dogs present in the dining room tested seropositive. Environmental tests were negative. These investigations confirmed the occurrence of 15 clustered cases of tularemia, contracted on the evening of August 4 at a mill in the Vendée, an endemic area for tularemia, and demonstrated the existence of pulmonary forms in France. (R.A.)