It is now widely acknowledged that climate change is occurring as a result of anthropogenic greenhouse gas emissions. Although human settlements have always been threatened by various types of risks and hazards, climate change is expected to exacerbate the intensity and frequency of many of these hazards. This could have severe consequences for supply, transmission and distribution of energy, as the driving force of the majority of economic activities in urban areas. Responsible for a significant part of the global energy consumption, cities need to be well-equipped and prepared in the face of increasing climate change induced disasters. In recent years, resilience thinking has been increasingly used for examining how cities are ready to face imminent disasters. Despite the importance of energy for effective functioning of cities, there is still a gap in the urban literature regarding the definition of energy resilience and development a framework for its assessment. To fill this lacuna, this study aims to specify the main components of urban energy resilience and develop a conceptual framework for its assessment. Drawing on an extensive literature review, this study defines energy resiliency as a range of preparation, absorption, recovery, and adaptation measures that ensure availability, accessibility, affordability, and acceptability of energy supply, transmission and distribution over time. This definition is used for conceptualizing energy resilience assessment and can be used to design an urban energy resilience toolkit. Such a toolkit should cover various energy related aspects such as infrastructure; land use, urban geometry and urban morphology; resource management; urban governance; legal basis and regulations; and social and behavioural aspects. The toolkit could be utilized by planners and decision makers to make better-informed decisions towards low-carbon and resilient urban development. The paper concludes by emphasizing that any energy resilience assessment toolkit should include criteria and indicators that address both mitigation and adaptation aspects of climate change. (C) 2015 The Authors. Published by Elsevier Ltd.