Protected areas are key instruments for conserving biodiversity and landscapes. Yet, conservation initiatives are still often struggling to accommodate people's needs, provoking conflicts, and lacking support from local communities. Our study combines environmental justice and ecosystem services approaches to provide a critical understanding of trade-offs between people's interests and conservation goals in the case study of Circeo National Park (Italy). Applying a qualitative content analysis of different materials and using a survey of local residents, we focus on three main objectives: analysing the implementation of the ecosystem services framework in policy documents and exploring how different people value benefits from nature; investigating the decision-making process in terms of participation, information and communication strategies; and identifying how conservation policies generated different allocations of benefits, burdens and inequalities among social groups. The integrated approach applied in our study highlights ways to systematically uncover perceived injustices and identifies potential conflict lines. In the long run, this approach might help to increase the public acceptance of protected areas by fostering sustainability also in its often-overlooked social dimension.