This study was carried out in two stages. The first – a bibliographic review – was intended to update and widen the theory of discourse analysis and its application as a research technique. The second consisted of an interview and discourse analysis of the speech of teachers of a Psycho-pedagogical course, in relation to a specific theme: their knowledge of multidisciplinarity, interdisciplinarity, transdisciplinarity and complex thinking, and the relationship between these and psycho-pedagogy. Between the object, that which is represented, the reality, and its representation by means of the sign (according to the concept of Pierce, 1995) or the signifier (using the terminology of Saussure), there is always a concept, a mental image or mental construction of the perceived reality. We interviewed four teachers who, during the year 2004, gave lectures for the same Psycho-pedagogy course in the city of São Paulo. The object of this research is to investigate the teachers’ degree of familiarity with the concepts of multidisciplinarity, interdisciplinarity, transdisciplinarity and complex thinking, and the relationship between these and psycho-pedagogy. This led to the production of a specific outline in the analysis of their discourses, aimed at determining the coherence between the responses given to the various questions, and the depth with which they discoursed on the proposed theme.