West Nile Fever (WNF) is the most common arbovirus infection caused by West Nile Virus (WNV), which has been responsible for numerous epidemic outbreaks of disease among humans, birds and horses on all continents, with the exception of Antarctica, over the past two decades. On the territory of Ukraine, the earliest reports of cases of WNV circulation in humans and birds relate to the 70s of the XX century. In Poltava region WNF was first registered in 2011. Though the epidemiological and clinical patterns of WNF in Ukraine and Poltava region remain understudied, primarily due to the lack of alertness of practitioners to the problem of WNF and to broader access to laboratory diagnosis of the disease. The first clinical case of West Nile Viral encephalitis, registered on the territory of Poltava region, has been given and analyzed.