This paper explores the concept of sustainable hospitality. The relevance and status of this area of enquiry are assessed by discussing the current status of the concepts involved. These discussions are then linked to progress made in sustainable hospitality both in research and practical applications in the hospitality industry. At least six principal schools of thought within hospitality are noted: hospitality science, hospitality management, hospitality studies, the "three domain school", the systems thinking school and the pragmatic tradition. This complexity and lack of clear definition are problems. The differences between sustainability and sustainable development, and between weak and strong sustainability add further complexities. This paper shows that progress in both sustainable hospitality and tourism has been limited by these problems. A series of technical, ethical and commercial problems are discussed. However, while sustainable hospitality as a research area is still in its infancy, it is concluded that it is very relevant within the wider context of sustainable tourism research, based on its impact and its specific position within the social-ecological-economic systems under investigation. Key areas of future work are suggested, notably to better understand the impacts of hospitality on the triple bottom line, and to explore systems approaches towards implementation.