There has been brief but important discussion regarding the concepts of "oppression" and "anti-oppression" in the educational psychology professional practice literature. This article aims to both further and focus this discussion. In particular, the concept of "epistemological oppression" is introduced and the significance it has for the meaning-making and knowledge construction activities of educational psychology practice is explored. A conceptual application of two predominant theories of epistemological oppression, Standpoint Theory and the Three Levels of Epistemological Oppression theory, is made with regard to the psychological assessment of special educational needs (SEN). It is posited that as psychological assessment of SEN is fundamentally an epistemological endeavour these two theories provide a crucial framework through which educational psychologist (EPs) may base reflective practice in order to realise and ameliorate potential oppression. It is concluded that EPs have a responsibility to orient themselves toward the potential for epistemological oppression in their work and help towards its amelioration.