The fact that the emergence of “technoscience,” resulting from the coalescing of science and technology, may have serious social and cultural impact has been debated in recent years particularly with regard to the field of medicine. The present article is exploring the scope and limits of the “technoscientization” of medicine using the example of rare disease patient associations. It is investigated whether and to what extent these organizations adopt technoscientific illness identities and subscribe to the research priorities and objectives of (...) biomedicine. In addition, it is analyzed whether Paul Rabinow’s highly influential concept of biosociality entails a technoscientific model of identity or, quite to the contrary, offers a framework for contesting biomedical ascriptions of identities. As the article shows, patient associations do refer to technoscientific definitions of diseases yet constantly modify and transform them based on their everyday illness experiences. Likewise, the “biosociality” of rare disease patients emerges from the shared experience of having been neglected by mainstream medical research rather than from supposedly objective biomedical classifications. (shrink)