This paper aims to offer a synthetic but exhaustive picture of the Psychology of Liberation. In the first section the cultural context in which this orientation was born and developed is described. Influences from and overlapping aspects with Social sciences in general and especially Latin-American ones are indicated. The description of the evolution of Psychology during the 70s introduces the main transformations proposed by the Psychology of Liberation. Key constructs and theoretical principles of the discipline are also stated. Martín- Baró is definitely a prominent figure of the Psychology of Liberation, but also other disciplines (mainly pedagogy, sociology and philosophy) and authors (mostly Freire and Fals Borda, but also Montero herself) gave important contributions to its development. Psychology of Liberation is presented as a transversal framework that employs a complex methodology which psychological work in many different areas may benefit from, even in contexts much different from Latin America.
Keywords: Psychology of liberation, action-research, latin american psychology.