Climate change is definitely one of the greatest challenges of human development in the 21st century. Climate change is expected to increase the risk of communicable diseases in Europe. This impact will depend not only on local climatic conditions, but on other factors, such as current infrastructure, public health services, biodiversity specificity, etc. The population in Bosnia and Herzegovina, Croatia and Serbia has been severely affected by the floods caused by cyclone Tamara in 2014. The basic mode of transmission of the disease caused by the West Nile virus is the bite of the infected mosquito. The West Nile virus is not transmitted among humans through contact, nor can it be transmitted from infected birds to humans without mosquito bite. The aim of the study was to analyze and present the trend of this disease in the period 2014-2018 and to show the connection between the spatial occurrence of cases and location of the flooded area in 2014 in the Republic of Srpska. Using the descriptive method, the demographic data of the patients were analysed, the most common clinical form of the disease and the incidence of the disease in the period 2014-2018 was analysed. The cases were mapped and we analysed the connection of the case and location that was flooded. The incidence ranged from 0.79 in 2014 to 0.43 in 2018. Patients were of all age groups and both sexes, most commonly cases from rural areas (78%). The most common clinical form of the disease is shown, which were symptoms of the central nervous system infection. Out of the total number of patients, 94% were from flooded areas. All reported cases have been diagnosed at the Institute of Microbiology at the University Clinical Center of Republika Srpska and were reported as probable cases in accordance with the international case definition of communicable diseases. However, it is crucial to implement internationally endorsed procedures as a clinical alghoritm for the confirmation of the case in accordance with the laboratory criteria for the case definition. The occurrence, frequency and spatial distribution of cases indicates a possible connection with the floods in 2014.