Agrifood systems are essential for providing nourishment, sustaining livelihoods and shaping cultural identities. However, they also generate significant environmental, social and health hidden costs that are not reflected in market prices. These costs stem from unsustainable practices that contribute to climate change, natural resource degradation and the unaffordability of healthy diets. The 2023 and 2024 editions of The State of Food and Agriculture apply a true cost accounting (TCA) approach to estimate these costs, revealing that global hidden costs likely exceeded USD 10 trillion (PPP) in 2020. This report presents the 2024 TCA estimates for 12 Small Island Developing States (SIDS) – a diverse group of countries in terms of geography and income levels, facing unique vulnerabilities due to their size, remoteness and exposure to environmental shocks. The national-level estimates presented here offer a foundation for more in-depth and targeted assessments, supporting stakeholders in identifying priorities and guiding action towards more sustainable agrifood systems.