Abstract Background As emergency department (ED) leaders started integrating geriatric emergency guidelines on a facultative basis, important variations have emerged between EDs in care for older patients. The aim of this study was to establish a consensus on minimum operational standards for Geriatric ED care in Belgium. Methods A two-stage modified Delphi study was conducted. Twenty panellists were recruited from Dutch and French speaking regions in Belgium to join an interdisciplinary expert panel. In the first stage, an online survey was conducted to identify and define all possible elements of geriatric emergency care. In the second stage, an online survey and online expert panel meeting were organized consecutively to determine which elements should be recognized as minimum operational standards. Results Between March 2020 and February 2021, the expert panel developed a broad consensus including ten statements focusing on the target population, specific goals, availability of geriatric practitioners and quality assurance. Additionally, the expert panel also determined which protocols, materials and accommodation criteria should be available in conventional EDs (39 standards) and in observational EDs (57 standards). Conclusions This study presents a consensus on minimum operational standards for geriatric emergency care in two ED types: the conventional ED and the observational ED. These findings may serve as a starting point towards broadly supported minimum standards of care stipulated by legislation in Belgium or other countries.