BACKGROUND: Metastatic medulloblastoma has a poorer prognosis than localised disease in part due to inherent properties of the tumour. 1H magnetic resonance spectroscopy (MRS) provides a powerful method for investigating tumour metabolism in vivo. METHODS: Magnetic resonance imaging and short echo time (Te 30 ms) single voxel MRS were performed on the primary tumour of 16 children with medulloblastoma prior to surgical resection. Tumour volumes were calculated using a segmentation technique and the MRS was analysed using LCModel. RESULTS: Patients with metastatic disease had primary tumours which were smaller (p=0.01), had higher levels of total choline (p=0.03) and lower levels of mobile lipids (p=0.04). CONCLUSION: Metastatic medulloblastomas have metabolite profiles indicative of increased cell growth and decreased cell death compared with localised tumours reflecting intrinsic differences in underlying biology. Localised tumours with an MRS metabolite profile similar to those with metastatic disease may be at increased risk of metastatic relapse.