OBJECTIVES: Addressing inequitable oral health access is a global priority. In Canada, community dental clinics (CDCs) play a crucial role in this endeavour, yet limited resources necessitate strategically targeting communities for interventions. Various methods exist for defining communities and measuring outcomes, but how CDCs determine their target populations is under-researched. This study aimed to explore how decision-makers planning an inner-city CDC define the population they intend to serve. METHODS: Data was collected through key informant interviews, document analysis, and field observations. Purposive sampling was employed to select key informants and documents related to clinic planning and design. The researcher was immersed in the data throughout the study, which underwent inductive content analysis facilitated by NVivo software. RESULTS: Analysis included semi-structured key informant interviews (n = 11), textual data from public sources and key informants (n = 9), and field observations totalling 275 hours over 1 year (2020-2021). Key informants agreed that the clinic served a "vulnerable" population, but definitions of "vulnerable" varied. Initial coding revealed two distinct patient groups with differing portrayals. Based on five patient characteristics Sossauer et al. (2019) described, one group was portrayed positively, while the other was depicted negatively. CONCLUSIONS: This study underscores the necessity of establishing a shared understanding of "vulnerability" in interdisciplinary projects like the CDC examined here. Assumptions about community groups hold significant consequences, shaping resource allocation, programme implementation, and policy decisions. It is imperative to critically assess who is making these decisions, their conception of vulnerability, and the repercussions of these beliefs on affected communities.