This study was conducted to perform a life cycle environmental assessment of ethylene glycol production in Iran’s petrochemical industry. Using a quantitative and systematic life cycle assessment approach, it aimed to identify and quantify the environmental impacts associated with producing one tonne of ethylene glycol and to determine the key hotspots. The methodology was developed in accordance with the ISO 14040 series. The system boundary was defined as gate-to-gate, and the functional unit was set as “production of one tonne of ethylene glycol.” The results indicated that the environmental impact profile of ethylene glycol production is significantly influenced by utility units and supporting processes. In the global warming impact category, electricity generation—and subsequently steam generation—accounted for the largest share of CO₂-equivalent emissions, highlighting the dominant role of fossil fuel–based energy supply in shaping the product’s carbon footprint. In human health–related categories, including carcinogenic effects and inorganic and organic respiratory impacts, electricity generation was also identified as the primary hotspot, reflecting the substantial contribution of combustion-related emissions and associated pollutants. By contrast, in the non-carcinogenic category, the industrial water production unit was the dominant contributor, underscoring the importance of chemical consumption and management of water-related flows in health-oriented impacts. Overall, the findings confirm that improving the environmental performance of ethylene glycol production requires an integrated approach that simultaneously focuses on optimizing energy use (electricity and steam), reducing combustion emissions, enhancing water and wastewater management, and improving waste management.