From the 1920s-1930s, studies aiming to get acquainted with the biting mosquito fauna in Hungary were intensified. The endemic incidence of malaria particularly affected the Southwestern and Northeastern parts of the country. Because of this, several malariastations were set up during the Second World War, in the Transcarpathian area: in the city of Uzhhorod (Ungvár) and Beregszász. The Uzhhorod Station started its activities in February 1940. Their duties included the education of the public, the development and application of defense methods of the time, and the medical treatment of patients. In order to achieve the natural mosquito clearance, Gambusia affinis fish were installed in the deeper brickyard pits. Due to their insecticidal effect, methyl green and naphtha derivatives were used as chemical agents. In the more affected settlements, terrain and water management works were carried out after mapping the terrain, which affected swampy and riverbed areas. The stations contributed to eradicating the problem, but it was possible to suppress the endemic presence of malaria only by the early 1950s.