Since 1989, PCdoB has been allied to the Workers' Party (PT) at the federal level, and, as such, it participated in the Luiz Inácio Lula da Silva administration and joined the "With the strength of the people" coalition, which elected his successor, Dilma Rousseff.

At the 20th Congress of the CPSU, Nikita Khrushchev had delivered the so-called "Secret Speech", which denounced the abuses committed by the Soviet state under Joseph Stalin's rule.

The party leadership prior to the rupture, primarily composed of revisionists, was formed in 1943 by João Amazonas, Maurício Grabois, Pedro Pomar, Diógenes Arruda Câmara, and Secretary General Luís Carlos Prestes, among others.

The PC-SBIC was ideologically grounded in the writings of Karl Marx and Friedrich Engels, and in the actions of Vladimir Lenin in the aftermath of the October Revolution, advocating democratic centralism and Marxism–Leninism.

Defeated factions dissolved, and a need to reorganize the party was established, as well as an outlining the tasks of communists in the struggle against fascism, and a declaration of war on the Axis, sending an expeditionary force to fight in Europe.

Many Communists marched willingly into the theater of operations in Italy, and the Party organized a broad movement in solidarity with the Brazilian Expeditionary Force (FEB).

These meetings were attended by Joao Amazonas, Mauricio Grabois, Camara Ferreira, Mário Alves, Jacob Gorender, Miguel Batista de Carvalho, and Apollonius.

The crisis between the Soviet Union and China reached its peak when the Chinese leader Mao Zedong criticized the ongoing process of de-Stalinization in the USSR, and accused Khrushchev of "opportunistic" and "reformist" deviations.

Subsequently, the party gravitated towards Maoism, considering only China and Albania socialist countries, and asserting that others were no longer revolutionary, but revisionist.

Following the principle of protracted people's war, PCdoB undertook to transfer ideology to the field, initiating the formation of a peasant army.

The area chosen for the irradiation of the future peasant army (along a Maoist line) was a region south of Para, near the border with Tocantins.

As there was originally little adhesion between locals, the party created the Freedom Union and the People's Rights (ULDP), whose manifesto contained the programmatic basis of the guerrillas.

In 1971, Army units discovered the location of the guerrilla nucleus and were deployed to cordon off the area, preventing it from spreading its operations to the north of the Amazon.

In the 3rd campaign of annihilation, the Army used "dirty tactics", including torture of civilians, and execution and beheading of prisoners, hiding the bodies where they would remain unknown for decades.

In the late 1960s, Marxist–Leninist Popular Action (APML), a group derived from the Catholic left, adopted a Maoist ideology and approached the PCdoB.

On 16 December 1976, the DOI-Codi-SP invaded a house on Pius XI Street, São Paulo, killing Pedro Pomar and Ângelo Arroio, torturing João Batista Drumond to death, and taking prisoner Wladimir Pomar (son of Pedro), Aldo Arantes, Haroldo Lima, and Elza Monnerat (the latter two former members of the AP), in an episode that would become known as the Massacre or Slaughter of Lapa.

Observing the failure of the rural guerrilla and the new policy adopted by China since Mao's death in 1976, PCdoB decided to break with Maoism.

In 1978, the party followed Enver Hoxha in his criticism of Chinese leaders, and considered Albania alone as a socialist country, the last bulwark of Marxism-Leninism.

In unionism, PCdoB initially adopted a policy of alliance with trade unionists linked to the PCB, adhering to CONCLAT in 1983, which included moderates and non-Marxists.

The main impact of these changes was the decision of PCdoB at its 8th Congress in 1992, with the slogan Vive Socialism, that Stalinism had failed, and to move closer to "classical" Marxism.

In the late 1980s, PCdoB supported the formation of a popular front to launch Luiz Inácio Lula da Silva's candidacy for President.

Since 2001, the party is led by Renato Rabelo (a former member of the Popular Action guerrilla group), who succeeded João Amazonas who died in the following year.

With the victory of Lula in 2002, PCdoB became part of the federal government, occupying the Ministry of Sports; first with Agnelo Queiroz, and later with Orlando Silva.

That same year, PCdoB achieved its first municipal administration of a state capital when PT's Marcelo Déda resigned in order to run as Governor of Sergipe and Edvaldo Nogueira took office as mayor of Aracaju.

That same year, it had its largest expansion of local representation, electing 40 mayors; some of them in big cities such as Aracaju, Olinda, Maranguape, and Juazeiro.

It covers only the initial phase of transition to socialism, determining the need for collective party action on some issues in the immediate to medium term.

[14] Its political and ideological identity was consolidated as opposing the so-called 1960s "revisionism", identified with the directions taken by the USSR after the 20th Congress of the Communist Party of the Soviet Union.

[14] During this process, PCdoB ranged from an approach that pointed to the class struggle as responsible for the fundamental changes that occurred in the Soviet regime, while on the other hand, it showed an economistic tendency, placing the problems of socialism around the development of productive forces.

[16] The party lists its electoral goals for the 2010 general elections as being the "consolidation of Communist presence in the institutions", the "enlargement of influence on lower classes" and "maintaining the democratic and progressive forces at the head of the national government".