During his adolescence, he studied at Eton College, and upon returning to Brazil, he became involved with socialism and communism under the influence of his first wife, who had been part of the intellectual circles in Paris at the time.

Through his mother, Guimarães was the great-grandson of the Baron of São João de Icaraí [pt] and the great-great-grandson of the Marquis of Paraná.

He belonged to a family of farmers and sugar mill owners in Rio de Janeiro, specifically in the cities of Niterói and Barra Mansa.

He also worked conducting inspections on farms for a British mortgage company, and by the end of 1928, he served as the superintendent of a fruit plantation owned by the Guinle family [pt] in Queimados, Nova Iguaçu.

[3] Guimarães returned to Brazil and became associated with the Brazilian Communist Party (PCB), joining it in late 1931 and taking on the role of mimeograph technician and general services.

Guimarães became part of the national secretariat of the PCB in early 1934, with Antônio Maciel Bonfim serving as the secretary-general at the time.

The armed movement failed, and the leadership of the PCB ordered the execution of Antônio Maciel Bonfim's consort, Elza Fernandes, on suspicion of betrayal.

While imprisoned on Ilha Grande, he attempted suicide and escapes until he was allowed to reside in a house near the prison with his second wife, Maria Nazaré Nunes Guimarães, and his children.

Guimarães died on 1 February 1968 as a result of polytrauma following a car accident on Presidente Dutra Highway, more specifically in the city of Volta Redonda.