Research on twins has tended to focus around the question of heredity/environment. As part of this, attention has been paid to how twins' family environments impact upon them. By examining twinship as a social identity, this article considers the social experience of twinship as it is framed by parent–child relations and also actively shaped by twins themselves. Sameness constitutes one central defining component of ‘twin’ identity within Western societies. In preparing their twins' bodies for public presentation, parents play a key role in communicating twin identity on their children's behalf. However, children also construct and convey their own identities through presenting their bodies in certain ways. Drawing on findings from a small-scale qualitative study of twinship, this article examines how twin identity is created, modified and reproduced by parents and child twins. It highlights the active role that twins take in constructing their own identities and in shaping the ‘twin situation’.