The son of a teacher and the youngest of four siblings, Ďuriš was born in the village Rovňany near Lučenec; he grew up in a multiethnic environment, attending both Hungarian and Slovak grammar schools.

[2] After completing military service upon his return from France, Ďuriš moved to Bratislava, where he was appointed organizational secretary of the KSČ in Slovakia, as well as editor of the newspapers Pravda and Ľudové denník.

Combined with his disagreements with President Antonín Novotný, Ďuriš's previous role in the campaign against bourgeois nationalists led to his gradual removal from positions of power from 1963.

In August 1968, Ďuriš, who had previously been known as a hardliner within the party, supported the Prague Spring and condemned the subsequent Warsaw Pact invasion of Czechoslovakia.

He was expelled from the KSČ in 1970, and went on to declare himself a "communist outside the party"; during the 1970s and 1980s, he wrote extensive memoirs where he condemned the Soviet model of communism as "imperialistic" and criticized his former rival Husák, by now President.