West Nile virus, a member of the Japanese encephalitis antigenic complex, has caused sporadic cases and outbreaks of human and equine disease in Europe. Environmental factors, such as heavy rains, floods, irrigation, and higher temperatures, can enhance mosquito populations and increase the incidence of West Nile fever. The 1996-97 outbreak in and near Bucharest, Romania, was the largest European outbreak since the 1980s, with over 500 clinical cases and a case-fatality rate of nearly 10%. The virus is transmitted primarily by bird-feeding mosquitoes, with *Culex pipiens*, *Cx. modestus*, and *Coquillettidia richiardii* being the main vectors in Europe. Wild birds are the primary hosts, and migratory birds play a crucial role in spreading the virus to temperate regions. The virus can cause a range of symptoms in humans, from mild fever and flu-like symptoms to severe neurological disorders, and can be fatal in older adults. Equine disease, known as Near Eastern equine encephalitis, has also been observed, with moderate to high fatality rates. The virus can persist in disease-endemic foci through various mechanisms, including hibernating female mosquitoes, transovarially infected progeny, and chronically infected vertebrate hosts. Global warming scenarios suggest that warmer and more humid weather may increase the distribution and abundance of mosquito vectors, potentially leading to more frequent and widespread outbreaks of West Nile fever in Europe. Surveillance and research are essential to understand and manage this reemerging mosquito-borne viral disease.West Nile virus, a member of the Japanese encephalitis antigenic complex, has caused sporadic cases and outbreaks of human and equine disease in Europe. Environmental factors, such as heavy rains, floods, irrigation, and higher temperatures, can enhance mosquito populations and increase the incidence of West Nile fever. The 1996-97 outbreak in and near Bucharest, Romania, was the largest European outbreak since the 1980s, with over 500 clinical cases and a case-fatality rate of nearly 10%. The virus is transmitted primarily by bird-feeding mosquitoes, with *Culex pipiens*, *Cx. modestus*, and *Coquillettidia richiardii* being the main vectors in Europe. Wild birds are the primary hosts, and migratory birds play a crucial role in spreading the virus to temperate regions. The virus can cause a range of symptoms in humans, from mild fever and flu-like symptoms to severe neurological disorders, and can be fatal in older adults. Equine disease, known as Near Eastern equine encephalitis, has also been observed, with moderate to high fatality rates. The virus can persist in disease-endemic foci through various mechanisms, including hibernating female mosquitoes, transovarially infected progeny, and chronically infected vertebrate hosts. Global warming scenarios suggest that warmer and more humid weather may increase the distribution and abundance of mosquito vectors, potentially leading to more frequent and widespread outbreaks of West Nile fever in Europe. Surveillance and research are essential to understand and manage this reemerging mosquito-borne viral disease.