In order to document the species richness of mosquitoes (Diptera: Culicidae) and their distributions in the Mexican state of Hidalgo, collecting trips were conducted to all physiographic regions (Coastal Plain of North Gulf, Sierra Madre Oriental, and Neo-volcanic Axis) and subregions of the state. Additionally, mosquito specimens from Hidalgo deposited in the Collection of Arthropods of Medical Importance (CAIM) were reexamined. A total of 3225 specimens were collected and studied and an additional 69 pinned mosquitoes and 15 microscope slides in CAIM were examined. The two Culicidae subfamilies Anophelinae and Culicinae, 8 tribes, 12 genera, 24 subgenera, and 56 species were documented. Of these, 4 tribes, 7 genera, 13 subgenera, and 26 species are new records for the mosquito fauna of Hidalgo. Nine species previously recorded were not found in the collections made during this study. Taxonomic notes, new distribution records, and comments about the medical importance of the species found are included.