EN
This paper is a comprehensive presentation of the role of ticks, especially those occurring in Poland, in the epidemiology of arthropod-borne diseases. Following paragraphs review briefly principal diseases of viral, rickettsial and bacterial etiology with emphasis on natural circulation of pathogens between ticks serving as vectors and various vertebrates which function as tick hosts and pathogen reservoires. The vertical circulation of pathogens within the ticks population as well as modes of transmission of viruses, rickettsiae and bacteria by ticks to man are also outlined.