BACKGROUND: The patient's interpretation of the events and decisions leading up to consultation with a healthcare professional for symptoms of brain cancer is under researched. The aim of this study was to document responses to noticing the changes preceding a diagnosis of brain cancer and living with them, focusing on appraisal of changes and the decision to seek (and re-seek) help, with attention to the psychological processes underpinning the appraisal and help-seeking intervals. METHOD: In this qualitative study set in Eastern and NW England, in-depth interviews with adult patients recently diagnosed with primary brain cancer and their family members were analysed thematically, using the Model of Pathways to Treatment as a conceptual framework. RESULTS: 39 adult patients were interviewed. Regarding the appraisal interval, cognitive heuristics were found to underpin explanations of changes/symptoms. The subtlety and normality of changes often suggested nothing serious was wrong. Common explanations included stress or being busy at work, or age and these did not seem to warrant a visit to a doctor. Explanations and the decision to seek help were made within the social context, with friends, family and work colleagues contributing to appraisal and help-seeking decisions. Regarding the help-seeking interval, barriers to seeking help reflected components of Social Cognitive Theory, and included having other priorities, outcome expectations (e.g. 'feeling silly', not sure much can be done about it, not wanting to waste doctors' time) and accessibility of a preferred healthcare professional. CONCLUSION: Application of psychological theory facilitated understanding of the influences on cognition and behaviour. The study highlights implications for theory, awareness campaigns and potential opportunities promoting more timely help-seeking.