This paper considers the experiences of adults conceived following sperm donation, who were registered with a voluntary DNA linking register and considers: how awareness of being donor-conceived affected their identity and family relationships; and the process of searching for their donor and donor-conceived siblings. The views and experiences of donor-conceived adults has, until recently, been a relatively neglected research area. This study is the first, to our knowledge, to consider the experiences of donor-conceived adults using a DNA-based register. This paper presents qualitative data from a questionnaire-based study with 65 adults conceived following sperm donation. It examines how ideas of relatedness, kinship and identity are enacted and how narrative certainties are challenged by opening up new conceptions of what it means to be ‘related’. No single story of being donor-conceived emerged – with competing narratives about the effects and implications for respondents’ kinship relationships and sense of identity. The knowledge of being donor-conceived could be both a powerful disrupter and a consolidator of existing family relationships. This study sheds light on how identity and kinship relationships are negotiated and managed by donor-conceived adults, both with their existing family and donor ‘relations’, and how these can change over the life-course.