While distance education (DE) is often considered as a means to provide mathematical education to students in remote locations or to promote the professional development of mathematics teachers, this article reports a case showing that DE may also be useful in providing mathematical instruction to individuals who are marginalized or disadvantaged due to their psychological or social conditions. In particular, we present the case of a young male convict with impulse control disorder (ICD) to whom DE made it possible to follow mathematical instruction adapted to a prison environment, which again helped him to modify his attitude towards the study of mathematics. Furthermore, the DE-setting provided him with an environment in which he could control his ICD-related outbursts originally triggered by the mathematics lessons and the associated feedback processes. We argue that DE has unforeseen potentials in terms of mathematical education for learners who are disadvantaged due to their psychological and social conditions.