<p>This paper by Working Group 1 of RILEM TC 309-MCP presents a critical review of life cycle assessment (LCA) studies on carbonated recycled concrete aggregates (CRCA). Carbonated products can offer significant environmental benefits, particularly by permanently storing CO₂. However, these environmental benefits must be assessed through a comprehensive LCA. A critical analysis of 16 peer-reviewed LCA studies on CRCA reveals several methodological inconsistencies: varied assumptions regarding system boundaries and handling multifunctionality; different end-of-waste criteria and attribution of environmental burdens and benefits among co-products; limited disclosure of key information, including, e.g., technical characteristics of CRCA products, CO₂ uptake and CO₂ sources; and unclear interpretation of negative impact results, without proper distinction between avoided emissions and carbon removals. Overall, the Global Warming Potential (GWP) results for unbound CRCA vary between − 48 and 14&#xa0;kg CO₂e/t CRCA within the analysed studies. These findings underscore the need for harmonised LCA methodologies and transparent reporting to enhance the reliability of LCA studies. A set of methodological recommendations is proposed to enhance LCA consistency, aligned with general LCA guidance and best practices, while being tailored to the specific context of carbonated products. The recommendations cover system boundary definition, multifunctionality handling, modelling of CO₂ flows, reporting of life cycle inventory information, and interpretation of LCA results. This work aims to support both researchers and practitioners in conducting more accurate and comparable LCAs on CRCA and other mineral carbonation products, ultimately contributing to the wider adoption of enforced carbonation within the construction sector.</p>