Sustainability issues have arisen also in luxury retailing; the paper aims at investigating the role played by flagship stores in expressing the sustainability commitment of luxury fashion brands and at defining the key features of in-store sustainability communications. Through a qualitative research design, a conceptual framework has been proposed on how flagship stores should be designed and managed to display a commitment towards sustainable development. Findings identified for the first time the distinctive aspects of sustainability communications delivered within and through flagship stores, and revealed that such in-store communications can support luxury fashion retailers in making stakeholders aware of their sustainability commitment.