Arboviruses do not represent a based-related phylogenetic group, but they are all transmitted by arthropods. Fifty arboviruses pathogenic for animals (including humans) have been reported, belonging to the families Asfarviridae, Bunyaviridae, Flaviviridae, Orthomyxoviridae, Rhabdoviridae, Reoviridae, and Togaviridae. A wide variety of hematophagous arthropods transmits the arboviruses: biting midges, cimicid bugs, mosquitoes, sand flies, and ticks. The vector acquires the infection by blood feeding from a viremic host and transmits the virus to a new host by the oral route (inoculating infected saliva). However, vertical transmission routes already exist (transovarial, venereal). Arbovirus can be amplified by a diverse range of vertebrate hosts including birds, rodents, equines, humans, and monkeys. Through biological evolution and cultural development, human beings were able to modify the environments according to their needs. Thus, deforestation has produced new areas for agriculture, livestock, farming activities, and urbanization. These anthropogenic activities have produced great changes to host and vector communities and population abundance, sometimes driving emergence and reemergence of arboviruses. In this chapter, we give a general view for most important aspects of arboviruses, their classification, transmission and maintenance mechanisms, ecology, and emergence process.