<p>Science–policy interfaces (SPIs) are critical for aligning biodiversity knowledge with planning and decision-making across governance levels. Nevertheless, a persistent challenge is how SPI can help public institutions move beyond linear knowledge transfer toward more deliberative, mutual learning approaches at the local scale. This study uses the municipality of Mafra, Portugal, as a case to illustrate how local institutional actors perceive and assign meaning to ecosystem services (ES). Grounded in socio-cultural valuation and using deliberative techniques, free elicitation, and participatory mapping, the research captures locally prioritized ES. It organizes them within the Common International Classification of Ecosystem Services (CICES). While this study does not quantify ES, it provides a socio-cultural valuation framework that can inform future assessments of locally relevant services and support the alignment of municipal planning with international sustainability goals. Findings reveal that perceptions are deeply context-dependent, shaped by institutional roles and disciplinary perspectives. Spatially explicit and deliberative tools broadened awareness of less tangible services, shifted ES prioritization, and surfaced overlooked perspectives. Although translating local knowledge into standardized classifications posed methodological challenges, integrating participatory methods with structured frameworks appears to support institutional learning. It may enhance policy relevance, suggesting a potentially valuable direction for future approaches. Overall, this research demonstrates how participatory mapping can make global ES frameworks more responsive to local realities, offering a transferable approach to inclusive and context-sensitive sustainability governance across diverse geographical settings.</p>