As paediatric HIV treatment has become increasingly available across the world, the global perinatally infected cohort is ageing. However, we know surprisingly little about what it is like to grow up with HIV in resource-stretched settings. We draw on findings from a prospective, qualitative study with HIV-positive children, their carers and healthcare workers from four clinics in Uganda and Zimbabwe to examine children's experiences of living with HIV on treatment. We consider how the HIV experience is made in a symbiotic relationship between children, carers and healthcare workers and shaped by broader discourses. Despite the radical development in prognosis for children, their experience of HIV is largely constructed in relation to a language of 'sickness' through the promotion of medicalised talk and the recounting of past illness stories. This narrow narrative framework both reflects and reproduces core dimensions of the lived experience of growing up with HIV, which emphasises an absence of resilient healthiness in the face of ongoing vulnerability and risk. The challenges that children encounter in articulating alternative narratives that prioritise the relative buoyancy of their health is indicative of the broader uncertainty that exists around the future for these children at this point in the epidemic.