The prediagnosis period of 74 children with primary brain tumours was assessed to examine their presentation and reasons for any delay in diagnosis. Medical case notes were reviewed and parents were interviewed and asked to complete psychological questionnaires. Mean (SD) duration of clinical history was 20.0 (29.1) weeks. Most common symptoms were vomiting (65%) and headache (64%). Only 34% of headaches were always associated with vomiting and only 28% occurred 'early morning'. Changes in the child's personality (47%) were also common. The average number of consultations before diagnosis was 4.6. Migraine was diagnosed in 24% of children and a psychological aetiology in 15%. One quarter of the children had altered levels of consciousness on arrival at the unit. Results indicate that delay in diagnosis still occurs, despite strong parental concern. The nonspecificity of symptoms and a high incidence of psychological symptoms may confound the clinical picture and are considered along with other possible contributory factors.