In the 1960s, Santos also began to participate in the liberation movement for Portuguese-speaking African countries. She was imprisoned in the early 1970s for her work with the Brazilian Communist Party. After her release, she chose to leave Brazil. Santos rejected invitations to move to the then-Soviet Union and instead chose to self-exile in Africa, where she stayed for around five years. She actively participated in the liberation movements of Guinea-Bissau and Angola as a guerrilla. She also worked on cultural development and literacy projects, contributing to cultural reconstruction in Guinea-Bissau, Angola, and Cape Verde.