Historic cores are essential city areas that preserve cultural heritage, urban fabric, and architectural identity. Despite their cultural and architectural significance, historic cores face challenges in adapting to modern urban needs and there is a lack in achieving a comprehensive process that helps in reviving them. Urban recycling has emerged as a transformative solution, revitalizing and repurposing underutilized or deteriorating spaces while preserving their historical essence. While the concept of sustainability, which seeks to meet current needs without compromising future generations, is at the heart of urban recycling. By balancing environmental protection, social equity, and economic growth. This paper introduces sustainable urban recycling as a holistic approach to address the environmental, cultural, social, and economic goals within historic cores. It emphasizes how this process can safeguard heritage while meeting diverse urban needs, improving residents' quality of life, and ensuring long-term urban sustainability. By exploring the goals of each aspect, the study highlights the potential of sustainable urban recycling to transform historic cores into thriving, inclusive, and resilient urban spaces for current and future generations. Since the sustainable urban recycling goals have not been evaluated before in different historical cores, a comprehensive analysis of two different case studies has been implemented in Bologna, Italy, and Historic Cairo, Egypt to identify the importance of the goals and how they are interdependent and must be achieved simultaneously to achieve a successful historic core for the current community and for the future generations.