The management of a World Heritage Site must have an intergenerational and sustainable perspective that leads to the development and implementation of policies for its sustainability. The purpose of this research is to expand knowledge on whether and how World Heritage Sites include sustainability dimensions in their management processes. Sustainability is envisioned as a multifaceted concept made up of financial, heritage, sociocultural, and environmental perspectives. A case study has been carried out at the Royal Alcazar of Seville, a UNESCO World Heritage Site since 1987. The findings highlight how sustainability dimensions intertwine with its management system. They also indicate that the financial and heritage dimensions are those that remain the most developed and that sociocultural and environmental dimensions are gaining prominence in management processes. Managers of other heritage sites can benefit from this research by acknowledging the role that all dimensions of sustainability play in the management processes of their organisations.