The transformation of traditional cities to smart cities becomes increasingly important for the actors that interact with it; Government, public and private organizations, and citizens in general, in addition to making easier its implementation thanks to the development of ICTs (Information and communications technology). Each project deals with specific needs according to the city's characteristics, however, it is possible to establish a general methodology for developing this transformation. The present article develops a methodological proposal for the implementation of a Smart City which includes five stages; analysis of current situation, preparation of a work plan, strategic formulation, action plan and management plan. Each stage is developed by integrating components such as infrastructure, technologies, processes and human capital in order to satisfy established strategic objectives and, overall, to create a better quality of life of its inhabitants and a sustainable environment.