Whilst preliminary research suggests an impact on neurocognitive dysfunction in survivors of leukaemia treatment there is little tangible research with a primary focus in leukaemia patients undergoing bone marrow transplant (BMT) . As survivorship numbers for children with leukaemia grows, attention shifts to quality of life and side effects of treatment. This study uses validated measures to explicitly define the short, medium and long term neurocognitive and quality of life (including sleep) outcomes associated with paediatric patients undergoing BMT leukaemia. Additionally, it remains unclear which conditioning treatment in leukaemia results in more statistically significant side effects in the short, medium or long term. Therefore, this study compares two standard pre-BMT conditioning therapies (1. Total Body Irradiation combined with chemotherapy and 2. Chemotherapy only) in a subset of patients with Acute Lymphoblastic Leukaemia (ALL) enrolled in the study. This study aims to accrue 150 participants in total. Thus far, neurocognitive and quality of life assessments have been conducted for consented participants (n=15), before BMT conditioning treatment begins. The study assesses each participant’s quality of life and sleep at 6 month intervals, and assesses neurocognitive function at 1, 3 and 5 years post baseline. Currently two participants have reached their 3 year neurocognitive assessment, with the majority of participants just completing their 1 year neurocognitive assessment. The study has reported a high level of feasibility as rated by parents in a pilot study. As the study is ongoing further results are not yet available and this paper will highlight the importance of understanding the long term neurocognitive effects that survivors of childhood cancer face. The implications of the study include identifying the key impacts associated with BMT and standard conditioning regimens, and the provision of early intervention services to minimise and/or prevent long term difficulties in mental health, education and vocational functioning.