The genus Hyalomma includes several tick species of medical and veterinary importance and is known to act as a vector of emerging pathogens. In Western Europe, the distribution of Hyalomma lusitanicum, which displays both ambush and active host-seeking behavior, is expanding. Its involvement in the transmission of Crimean- Congo hemorrhagic fever virus (CCHFv) is strongly suspected. This study aims to describe its distribution in southeastern France and assess the presence of CCHFv. Since 2024, CESPA (French Armed Forces Center for Epidemiology and Public Health) has conducted field surveys in the Crau Plain to evaluate the risk of CCHF for military personnel. Tick collection has been performed using dragging, CO2 traps and host sampling. Specimens were morphologically identified and analyzed using molecular methods for CCHFv detection. A serological survey is also being conducted in livestock and wildlife, alongside a surveillance system for tick bites among military personnel, which has already recorded four cases of H. lusitanicum bites. In 2025, 7,550 ticks were collected, of which 7,165 were identified as H. lusitanicum. Three additional Hyalomma species were also detected. All developmental stages of H. lusitanicum were observed in the field. The species’ host range was confirmed, with adults found on wild boar and cattle, while the presence of rabbit warrens appears to support its establishment. Its activity peaks during hot and dry periods. PCR testing of environmental ticks was negative for CCHFv. Analyses of ticks collected from animals are ongoing. However, two bovine serological samples tested positive. These findings confirm the establishment of Hyalomma lusitanicum in southeastern France, representing a potential public health concern. Continued spatiotemporal surveillance and molecular investigations are needed to better assess the risks associated with its ongoing emergence.