There are several social actors involved in the process of constructing the social meaning of dyslexia--namely, parents, teachers, educational authorities and organisations representing dyslectics. Some of these actors emphasise the constructive social powers related to the dyslexia label, while others perceive dyslexia as diagnostic reasoning counter productive to the learning processes. In the discussion of this paradox, this article uses sociological medicalisation theory as a provider of perspectives on medical labelling as contested, and on how the labelling process is socially structured. Empirically, the article is based on four studies in Scandinavia of the construction of dyslexia in different social settings, such as individual life stories, parent stories, educational politics and the legal system. The medicalisation perspective is found most useful for the understanding of undesirable effects. To understand reported experience of medical labelling as empowering, other sociological perspectives are more useful.