Current projections indicate that by 2050, two in every three people will live in urban areas, and that cities will accommodate 3 billion people during this period. Cities are consuming three-quarters of the world's energy and causing three-quarters of global pollution. To reduce these impacts, new technologies have been considered in the development of smart sustainable cities, but technology has not always favoured the idea of sustainable consumption. To address this issue, we have aimed to focus on identifying the role of sustainable consumption within implementations of smart cities’ projects across Europe. We have selected a set of smart city projects in 76 cities in Europe from CONCERTO initiatives, Mapping Smart Cities in Europe, Energy Study for the Stockholm Region and Joint European Support for Sustainable Investment in City Areas and classified them according to: smart governance, smart mobility, smart living, smart environment, smart citizens and smart economy. Furthermore, we established a number of categories for the classification of the evaluated projects based on their relevance to sustainable consumption, and considered several solutions for the integration of sustainable consumption in smart sustainable cities. The results show that in 18.9% of the projects, sustainable consumption is not relevant at all. The second classification shows the percentage of the remaining categories where sustainable consumption is relevant; 8.3% consider sustainable consumption as relevant even though it was not implemented in the project. These cities aim to achieve a higher level of sustainable consumption, which is expected to be included in future projects. If they keep themselves in this category, their behavioural consumption patterns will not change and the impact of citizens on the cities will remain the same. The majority of the projects, 54.2%, implemented technology to reduce consumption but if the projects do not coincide with the behaviour of citizens, a big rebound effect will occur. 37.5% of the projects consider relevant sustainable consumption to its full potential and this can change citizen’s behaviour. In conclusion, sustainable consumption is relevant in most of the projects analysed, with new technologies available to help energy savings and reduction of our consumption. However, if there is a lack of smart consumption from the citizens, the technologies available might not be sufficient and consumption could increase. One quarter of the analysed smart cities projects still do not consider the consumption behaviour of the citizens. This can be changed through campaigns and explanations targeting the population on how to manage and reduce energy and resource consumption. To reduce the negative impact of the cities’ growth, projects considering smart sustainable cities need to integrate sustainable consumption policies that account for citizens' behaviour.