After Paulo's short-lived career as a lawyer, he turned to teaching Portuguese in secondary schools (1941-1947). He later worked in adult education and workers' training, and became the first Director of the Department of Cultural Extension of the University of Recife (1961-1964). Paulo quickly gained international recognition for his experiences in literacy training in the Brazilian Northeast, particularly the experience of literacy training in Angicos, Rio Grande do Norte, that led the populist government of Joao Goulart to appoint him in 1963 as President of the National Commission on Popular Culture. After the military coup d'etat of 1964, he was considered a dangerous political pedagogue, was put in jail for seventy days and was later forced into a fifteen-year exile. Beginning with a short stay in Bolivia, he then went to Chile where he spent five years working for international organizations in the context of the Christian Democratic Agrarian Reform movement. After a short teaching at Harvard in 1969, Paulo Freire moved to Geneva to be an special educational adviser to the World Congress of Churches. He worked in Geneva for a decade and finally returned to Brazil in 1979 when the Brazilian military government lifted his travel restrictions.

Paulo, starting from a psychology of oppression influenced by the works of psychotherapists such as Freud, Jung, Adler, Fanon and Fromm, developed a "Pedagogy of the Oppressed." He believed that education could improve the human condition, counteracting the effects of a psychology of oppression, and ultimately contributing to what he considered the ontological vocation of humankind: humanization. Pedagogy of the Oppressed, which has been influenced by a myriad of philosophical currents including Phenomenology, Existentialism, Christian Personalism, Marxism and Hegelianism, calls for dialogue and ultimately conscientization as a way to overcome domination and oppression among and between human beings.

Freire's argues for system of education that emphasizes learning as an act of culture and freedom. He is most well known for concepts such as  "Banking" Education, in which passive learners have pre-selected knowledge deposited in their minds; "Conscientization", a process by which the learner advances towards critical consciousness; the "Culture of Silence", in which dominated individuals lose the means by which to critically respond to the culture that is forced on them by a dominant culture. Other important concepts developed by Freire include: "Dialectic", "Empowerment", "Generative Themes/Words", "Humanization", "Liberatory Education", "Mystification", "Praxis", " Problematization", and "Transformation of the World".