BACKGROUND: Childhood cancer survivors may develop a number of endocrine complications linked to organ failure, such as hypogonadism, diabetes and growth hormone deficiency. However, increasing evidence now suggests that total body irradiation treatment, specifically, is linked with future risk of insulin resistance, hepatic steatosis and dyslipidaemia, possibly because total body irradiation affects adipocyte differentiation and impairs subcutaneous adipose tissue depot expansion during times of positive energy balance. CASE REPORT: We describe a 20-year-old woman who developed pancreatitis with severe hypertriglyceridaemia (serum triglycerides > 300 mmol/l) that required plasmapheresis. She had received total body irradiation prior to her bone marrow transplant at age 6 years for relapsed acute lymphoblastic leukaemia. She developed ovarian failure at age 12 years. At age 15 years she was noted to have hyperglycaemia, increased blood pressure, hepatic steatosis and mild hypertriglyceridaemia. She presented with severe hypertriglyceridaemia and eruptive xanthoma, and developed pancreatitis 12 h after admission. She was treated with plasmapheresis and intravenous insulin and made an excellent recovery. We implicate and discuss total body irradiation as the major contributing factor to her severe hypertriglyceridaemia, compounded by worsening glycaemic control, oestrogen deficiency and a changing adult lifestyle. CONCLUSION: Children who have received total body irradiation are at risk of diabetes and an exaggerated form of the metabolic syndrome with hypertriglyceridaemia, which can be life-threatening. We suggest that survivors of total body irradiation treatment require careful lifelong monitoring of their metabolic status.