Few studies have attempted to correlate neuroimaging with outcome in patients with glioblastoma. Our aim was to evaluate the relationship between neuroradiological findings and survival in these patients. We studied 18 consecutive patients with glioblastoma who had undergone surgery and radiotherapy. We assessed the following features, using preoperative CT and/or MRI: tumour size, extent of necrotic area within the mass, extent of perifocal oedema and contrast enhancement. The mean survival was 14.2 +/- 5 months (range 6-22). The extent of radiological evidence of necrosis within the mass correlated significantly with survival time, whereas tumour size, perifocal oedema and contrast enhancement did not.