Modern cities currently face numerous challenges related to mobility, waste management, access to resources, etc. Smart Cities integrate information and communication technologies (ICT) to develop innovative solutions that can solve such challenges and create a higher quality of life for their citizens. Two elements need to be considered for smart cities to be successful. First, citizens must participate in the design of the smart city to take advantage of their ideas so that the smart city answers their real needs. Secondly, each city has its own unique characteristics that need to be considered to design a citizen participation strategy truly tailored and adapted to their respective context. In line with these two considerations, the goal of this paper is to identify the context factors that impact citizen participation strategies in smart cities. In order to reach that goal, we performed a qualitative case study of two cities that strive to be smart: Namur (Belgium) and Linköping (Sweden). This analysis allows us to understand how participation is implemented in two different cases and to infer the context factors that impact the respective strategies. Five context-factors have been identified in this study: the smart city consideration, the drivers for participation, the degree of centralization, the legal requirements, and the citizens’ characteristics. By identifying these factors, we can derive context-dependent recommendations about citizen participation for smart cities. These recommendations are then applied to the case of Brussels in Belgium.