Osteonecrosis is a recently established side effect of teenage and young adult (TYA) cancer, caused by the increasing use of corticosteroids in some treatment protocols. It is a long-term, disabling and painful bony condition, and there is no consensus on best management. A major UK cancer centre identified a gap in support for these patients and developed a TYA osteonecrosis support group. This article explains how and why the group was created, and describes themes frequently discussed by the young people in the group and the subsequent projects. The discussions revealed that osteonecrosis has a varied and significant effect on TYAs, ranging from ability to engage in work to enjoyment of life. Future plans include further exploration of TYA patients’ experience of osteonecrosis through qualitative research.