BACKGROUND: Childhood brain tumours have some of the longest time to diagnosis. A timely diagnosis may have a role in reducing anxiety in waiting for a diagnosis and subsequent morbidity and mortality. We investigated where the opportunities for an earlier diagnosis were, and for which anatomical locations this strategy will most likely to be effective. METHODS: A record-linkage cohort study of patients diagnosed aged 0-24 years with a primary intracranial tumour between 1989 and 2006 in England, using records from the National Cancer Registry linked to hospital admission records from Hospital Episode Statistics (HES, 1997-2006) and primary care consultation records from Clinical Practice Research Datalink (CPRD, 1989-2006). Relevant neurological presentations were extracted from HES and CPRD. Temporal changes in presentation rates were estimated in generalised additive models. RESULTS: Frequency of presentation began to increase six months before diagnosis in primary care and three months before diagnosis in hospital. Supratentorial and midline tumours had the longest presentation history before diagnosis. Peri-ventricular tumours presented frequently in hospital (rate ratio = 1.29 vs supratentorial tumours; 95% CI = 1.12-1.48) or as an emergency (1.24; 1.01-1.51), and in primary care (1.12; 0.62-1.85). CONCLUSIONS: Opportunities for an earlier diagnosis are greater in supratentorial, midline or cranial nerve tumours, which have a longer presentation history than peri-ventricular, cerebellar or brainstem tumours. Common features before diagnosis include headache, convulsions, and growth or endocrine disorders. Focal neurological deficits are uncommon and emerge late in the pre-diagnosis period.