Definitions of neighbourhood in the Social Sciences are complex, varying in their characteristics (for example, perceived boundaries and content) and between residents of that neighbourhood (for example, by class and ethnicity). This study employs an under-utilised methodology offering strong potential for overcoming some of the difficulties associated with neighbourhood definitions. A mental mapping exercise involving local residents is showcased for an ethnically diverse working-class neighbourhood in south Liverpool. The results demonstrate distinctions between residents in the geographical demarcation of the area and the features included, with important implications for how neighbourhood is best measured and understood. We suggest that one size does not fit all in definitions of neighbourhood, and that mental mapping should form a more common part of a neighbourhood researcher’s toolkit.