Smart Cities has emerged as an important research challenge among IS researchers in recent years. The grand claims that have been done about the potential of Smart Cities are grounded in a wide range of IT-related artifacts that were designed in theory and/or implemented in practice. Today, due to the growth of the level of knowledge maturity in this context, IS research in this field is more focused on the development of a nascent Smart City theory. The key concepts introduced in literature were collected through an eight-steps systematic literature review [19] and analyzed using [20]’s concept definition matrix. Based on this, this paper aims at reflecting upon research methodologies for conducting IS research in this field, and demonstrates the suitability of Action Design Research [43]. A Smart City research project that successfully used this methodology is also described to further support this statement.