The aim of the presented study is to compare two documentaries that deal with the same personality – Klement Gottwald – President of the Czechoslovak Republic in the years 1948–1953. Based on selected films we want to analyse how the current social situation, state regime, results stemming from history knowledge and current history education are reflected in their content. For this reason, we chose a documentary from the Descendants and Ancestors series called Klement Gottwald made in 1986, as well as a documentary from the Red Presidents series called Unified in Fear – Klement Gottwald in 2018, since the aim was to compare images published before and after 1989.2 At the same time, we look at the issue from a didactic point of view, when we present specific possibilities of using the comparison of documentary films in history teaching. At the beginning, we briefly define what a documentary is. Next, we introduce the personality of Klement Gottwald from the point of view of modern historiography, and for an overview we name and briefly inform about some documentary films that were made about him. Subsequently, we focus on the basic data for the selected images and then we move on to the comparison itself, where we focus among other things, on pointing out the influence of communist propaganda. In this section we focus on specific common or different features of both documents and analyse them in detail. Finally, we offer several alternatives for the application of the comparison of documentary films in educational practice.