Technology is leading cities to build growth and development rediscovering the city as sustainable organism oriented to enhance smartness as concept and urban policy initiative and improve citizen participation as drivers for proceeding towards a sustainable development. Cities planning a smart development do not necessarily become sustainable cities. Cities can build relationships with their inhabitants involving people in public affairs and policies without developing smart initiatives. Sustainability of cities relies on combining both smartness and participation as drivers enabling cities to design and build a path for driving a sustainable development.