We aimed to evaluate the feasibility and impact of community-based healthy food retailing interventions in two private food retailers in rural Newfoundland and Labrador. We conducted a case study realist evaluation which investigates the complexities, effects, components, and inner workings population health interventions (i.e. healthy food retailing). We conducted qualitative, semi-structured interviews with Ss before (November 2022) and after (February 2024) self-selected healthy food retailing interventions were implemented. Content analysis was used to code interview transcripts and create Context-Mechanisms-Outcome (CMO) statements representing how actions to create healthy food retailing work. Participating stores designed food retailing interventions aimed to increase healthy food availability, accessibility, affordability, and acceptability through new online ordering and delivery services with healthy food recipes (S1) and changes to store equipment and food packaging (S2). CMO statements highlighted determining factors of (i) community mindedness and feedback, (ii) store status in the food system, (iii) bulk buying, (iv) advertising and communication, and (v) level of establishment. Various concepts of smallness influence the ways in which the outcomes of interventions manifest in the store’s operations and its relationship with its customers. Success of healthy food retailing interventions were related to factors beyond the ‘food’ itself. The potential ‘mix’ of contextual and mechanistic factors that will generate the ideal outcome must be adequately appreciated to advance healthy food availability, affordability, and acceptability in rural food stores and communities. These explanatory findings can inform future design, adoption, adaptation, and implementation of healthy retailing interventions in NL and Canada.