In the 1930s, she joined the Brazilian Communist Party, through which she met her future husband, journalist Raul Ryff, with whom she had three sons. In 1936, she was arrested for her opposition to the "Estado Novo" dictatorship and her role in the failed Communist uprising of 1935. She was held in what became the infamous "Room 4" in the Casa de Detenção, in Rio de Janeiro, together with Nise da Silveira, Maria Werneck de Castro, Olga Benário Prestes, Eneida de Moraes and Eugênia Álvaro Moreyra. After her detention, Bandeira was exiled to Uruguay, together with her husband, returning in 1937.