The presence and distribution of Simulium erythrocephalum (De Geer, 1776) in the Valencian Autonomous Region is analyzed, an arthropod of medical-sanitary importance due to the marked anthropophilic characteristics exhibited and the tendency to carry out massive attacks. The increasing incidence registered in certain areas as a consequence of their hematophagy, and the meager availability of epidemiological, fauna, bioecological, and distribution data, have led to this study. A field study of 137 samplings was carried out from 2013 to the present in the 14 hydrographic basins of the Valencian Autonomous Region. The study variables were the presence or absence of preimaginal states, environmental and physical-chemical parameters of the water, bite data from the Generalitat Valenciana, population density and incidence of bites by municipality, and geographic location of the population areas. A scarce and reduced presence of the aforementioned species is revealed in the study area. Risk maps of human populations near the detected breeding areas are provided, and the epidemiological interest is discussed due to its vector capacity to transmit pathogens that cause disease. The number of bites registered between 2015, 2016, 2017, and 2018 in the seven health departments involved is provided. The general trend toward an increase in the number of cases is observed year after year, where the highest peaks in the number of cases coincide with the months of June, July, and August, and eventually, September and October. Surveillance and control programs to minimize the problem in the Spanish health system are needed.