<p>Rapid expansion of healthcare services and increasing dependence on disposable medical products has significantly increased medical waste generation and requires sustainable and efficient management practices. This study addresses the crucial problem of site selection for a medical waste sterilisation facility in Izmir, Turkey by integrating Geographic Information Systems (GIS) and multi-criteria decision-making (MCDM) techniques in a Triple Bottom Line (TBL) framework. Eleven GIS-based criteria, including slope, land cover and proximity to healthcare facilities, are evaluated and weighted using a fuzzy logic approach to generate a site suitability map. Following the identification of eight potential locations, the Fuzzy VIKOR method is used to rank them based on seven additional socio-economic and environmental factors such as land cost, population density and unemployment rate. The final selection process is complemented by incorporating the Hospital Proximity Index (HPI) to make the decision-making process more precise. The results indicate that Torbalı, Bülbüldere is the most suitable site, while Çeşme, Alaçatı emerged as the least viable alternative. The study underscores the need for integrating novel decision support mechanisms such as HPI and adopting a multipronged strategy for medical waste management. Furthermore, the proposed method provides a flexible framework of sustainable infrastructure planning that can be used for various site selection issues in urban planning.</p>