RT Journal Article T1 Sustainability, nationality and engagement: a study of designer fashion brands A1 Dourado, Pedro A1 Llovet, Carmen A1 Carrasco Polaino, Rafael AB Purpose: The fashion industry plays a significant role in causing environmental and social damage, driving a shift towards alternatives that promote responsible work methods and use more sustainable materials, such as designer fashion brands. Social media platforms like Instagram are essential for these brands to communicate their sustainability efforts to consumers. However, it is important to explore the factors that influence user engagement to make efforts more effective.Design/methodology/approach: After conducting a thematic analysis of all content posted on the Instagram accounts of 43 Portuguese and 40 Spanish designer fashion brands over a six-month period – between Lisbon and Madrid fashion week’s September/October 2022 and February/March 2023 editions – we used web scraping to examine 2,925 posts. This study investigates the impact of sustainability themes, Instagram post formats and brand nationality on user engagement, through the calculation of interaction or engagement indices for each post.Findings: Portuguese and Spanish designer fashion brands publish limited sustainability-related content on Instagram. This content generates low engagement, with variations based on brand nationality. Two tested factors influence engagement: the sustainability themes covered – the audience of Portuguese brands tends to prefer social sustainability topics – and the post format – videos generate more engagement with Spanish brands. The analysis of the content posted suggests that brands are not aligning with audience preferences, which may explain the low engagement with sustainability content.Originality/value: This study highlights the most engaging sustainability themes and post formats, offering valuable insights and guidelines for directing effective communication strategies for sustainability-related brands. It adds to the limited body of theory on sustainable fashion communication in Iberian countries and on engagement studies in the fashion sector. PB emeral insight YR 2025 FD 2025 LK https://hdl.handle.net/20.500.14352/124734 UL https://hdl.handle.net/20.500.14352/124734 LA eng NO Pedro Dourado, Carmen Llovet, Rafael Carrasco Polaino; Sustainability, nationality and engagement: a study of designer fashion brands. Management Decision 2025; https://doi.org/10.1108/MD-04-2024-0935 DS Docta Complutense RD 26 feb 2026