This final work contains a definition of West Nile virus, a way of its transmission, risk groups, clinical presentation of illness, diagnostic methods, prevention measures and treatment of infectious patients as well as the role of a nurse in caring for ill. West Nile virus is one of the viruses from the genus Flavivirus and the Flaviviridae family and belongs to a group of viruses commonly called arboviruses. It was first isolated in 1937. West Nile virus is common in countries of Africa and the Middle East. It is most commonly transmitted to humans by infected mosquitos. Birds are reservoir and the primary host while mosquito is a vector in transmission cycle. Culex is the most common form of mosquito that causes infection in humans. Cases of transmission from one human to another have not been reported. The increased rate of cases of ill is correlated with the period of the year, most of the cases of infections were recorded from August to mid- October. Incubation of disease is 13-14 days after mosquito bite. Approximately 80% of infected humans have no symptoms while 19% of the infected have mild flu-like symptoms. Along with elevated body temperature, some of the symptoms include nausea, vomiting, joint pain, lymphadenitis, etc. If rash appears, it is usually localized on back, abdomen and chest. Due to unspecified clinical presentation, disease often remains unrecognized. There is no specific therapy in the treatment. Symptoms are usually present for few days (3-6 days) after which a large number of patients successfully recover. 1% of infected population will develop complications in form of meningitis and meningoencephalitis. Mortality rate among patients with severe illness is between 3-11%. Since there is no vaccine to protect humans from infection, it is recommended to avoid mosquito bites.