Towards the end of the war, Brus returned to Poland with the Soviet controlled Polish First Army, only to find that his parents and sister had been murdered in Treblinka extermination camp.

[citation needed] After the war, Brus became the head of propaganda for the communist Polish Workers' Party (PPR).

In 1952 he wrote a propaganda textbook in which he expressed admiration for Joseph Stalin's work The Economic Problems of Socialism.

[2] In 1956, he remarried Wolińska, who had recently been fired from her job as a military prosecutor, accused of violating the rule of law in staged trials of Polish officers, which frequently resulted in executions.

In 1965, he testified in defense of Jacek Kuroń and Karol Modzelewski, who were on trial for their "Open Letter to the Party" calling for democratic reforms.

In 1989, together with Kazimierz Laski, he published From Marx to the Market, which expanded the arguments presented in Brus's 1961 work.