Mihailo Marković (1923–2010) was one of the leading members of the Yugoslav Praxis Group. Among other topics, he worked on the theory of communication and dialectical meaning, which makes his approach relevant for a contemporary critical theory of communication. This paper asks: How did Mihailo Marković conceive of communication? Marković turned towards Serbian nationalism and became the Vice-President of the Serbian Socialist Party. Given that nationalism is a particular form of ideological communication, an ideological anti-praxis that communicates the principle of nationhood, a critical theory of communication also needs to engage with aspects of ideology and nationalism. This paper therefore also asks whether there is a nationalist potential in Marković’s theory in particular or even in Marxist humanism in general. For providing answers to these questions, the article revisits Yugoslav praxis philosophy, the concepts of praxis, communication, ideology and nationalism. It shows the importance of a full humanism and the pitfalls of truncated humanism in critical theory in general and the critical theory of communication in particular. Taking into account complete humanism, the paper introduces the concept of praxis communication.