Climate targets for cities abound. However, what these targets really imply is dependent on a number of decisions regarding system boundaries and methods of calculation. In order to understand and compare cities' climate targets,there is a need for a generic and comprehensive framework of key methodological considerations. This paper identifies eight key methodological considerations for the different choices that can be made when setting targets for GHG emissions in a city and arranges them in four categories: temporal scope of target, object for target setting, unit of target, and range of target. To explore how target setting is carried out in practice, the climate targets of eight European cities were analysed. The results showed that these targets cover only a limited part of what could be included. Moreover, the cities showed quite limited awareness of what is, or could be, include in the targets. This makes comparison and benchmarking between cities difficult. (C) 2013 Elsevier Ltd. All rights reserved.