The article aims to analyse the development of the concept of totalitarianism in political sciences. The author puts an emphasis on international debates on totalitarianism. He also tracks the history of this concept, beginning with the nineteen twenties, in the context of Benito Mussolini’s rule in Italy and continuing with the legal perception of the term in Germany and Poland throughout the nineteen thirties, when the discourse moved to the US. It was in the last of those countries where the first conference on totalitarianism was organised. Pointing to the manner in which the concept of totalitarianism is used with regard to communism and Nazism also constitutes an important thread in the article.