As ambitions to ‘mainstream’ genetic and genomic medicine in the UK advance, patients are increasingly exposed to information about genomic data. Unlike the results of many other medical investigations which are linked to the time of sample collection, genomic testing providesimmortaldata that do not change across time, and may have relevance for relatives and generations far beyond the patient’s own lifespan. This immortality raises new ethical challenges for healthcare professionals, patients and families alike, such as ensuring consent for possible future interpretations; determining when genomic data are best sought (at birth, on illness etc) and reinterpreted; and balancing the confidentiality of patients and duties of care towards others. This paper reports on qualitative work exploring the perspectives of patients and relatives participating in genomic testing, and suggests that their engagements with this immortality are shaped by: the contrast between the simplicity of sample provision and information gathered; understandings of heritability; and notions of genomic data as a collective resource. We discuss the implications this holds for practice and argue that the immortality of genomic data must take a more prominent position in patient and healthcare professional interactions.