Posthumanism provides openings to think differently about ageing and assistive technologies within the phenomenon of elderliness, the latter being defined as a relational social-material phenomenon enacted by the intra-actions between humans and non-humans, which dynamically configure and reconfigure it. Such an understanding is indebted to Karen Barad’s agential realism. This theoretical framework is applied to move beyond social and bio-medical models that frame ageing respectively as a cultural fact and as physical and cognitive decay. Posthumanism shifts academic research and professional design into an alternative view of ageing and assistive technologies as inseparable. Such a view confronts professionals within and outside academia with new problems, questions, opportunities and solutions, and invites them to be responsible, suggestive, creative and visionary in their making and re-making, framing and re-framing of the phenomenon of elderliness.