Thirty-nine species of mosquito (Diptera: Culicidae) have been reported from the Mexican State of Coahuila, however, no systematic survey by county has been done. Many mosquito species vector diseases that affect humans, including dengue fever vectored by Aedes albopictus (Skuse). Better knowledge of the distribution of mosquitoes will aid public health program planning. Mosquito adults and larvae were collected from 28 counties in Coahuila; 592 larval slide mounts were prepared from different aquatic habitats, and 1447 adults were pinned. Twenty-two species, two of which were not reported before, were identified by county. Mosquito abundance, diversity and habitat information also are provided.