Climate disturbs urban systems with unusual events, making climate change preparedness a hot-topic in strategic regional planning discourses. Due to their complex structure, metropolitan regions require a comprehensive perspective including all services and sectors to determine climate change threats and provide effective strategies. This study aimed to identify priority planning areas in the Istanbul Metropolitan Region in terms of climate change vulnerability and risk levels to reveal sectors having the highest threats and requiring urgent improvements for climate change resilience. Istanbul is the largest metropolitan region in Turkey which has a country-wide hinterland, so it was chosen as the case study area. Priority planning areas represent the most important management areas of the regional government related to regional climate associated vulnerabilities and risks. Regional systems were defined by 11 urban sectors (culture, biodiversity and ecology, infrastructure, materials, land use and development, transportation, energy, water resources, agriculture and health) and 25 planning areas as components of the system likely to be impacted by climate change. To assess priority levels of planning areas, in-depth interviews were conducted with experts, representatives of companies, institutions, scientists, academics and researchers, and a vulnerability-risk matrix developed to rank the planning areas. The results of this study revealed that urban risk areas, heat, biodiversity, water supply and storm water management have the highest priority scores, while waste collection and cycling the lowest. These results may be a guide for regional governments addressing the starting point of climate change preparedness actions and important for enlightening paths towards more sustainable and resilient cities during climate change.