This bachelor thesis project presents an investigation into filarial nematodes (Dirofilaria repens, Dirofilaria immitis, and Setaria tundra) in Hungary, addressing four key objectives. Through field-collected data and molecular methods, it estimates their distribution across the country, providing crucial insights into their ecological range. By comparing the transmission potential of native and invasive mosquito species, the study sheds light on the dynamics of nematode spread. Additionally, it delves into infection patterns across different host species and geographical regions, unraveling the complexities of host-parasite interactions and highlighting the public health concerns associated. Finally, it explores the phylogenetic patterns of these nematode species, offering insights into the evolutionary history and dispersal across various regions.