Smart city is a strategy that aims at employing technology to improve life quality in urban areas. Among its main objectives, the environment quality is the top one. The EU vision on smart cities is strongly focused on energy efficiency, on nearly-zero energy buildings, on the reduction of CO2 emissions and so on. Therefore, some aspects of the smart city overlap with the idea of green city. Green city is an older but always updated vision, that aims at creating cities with a lower environmental impact, able to reduce the consumption of natural resources and to improve the quality of air and water.This study is designed to understand if smart city and green city have similarities, to what extent they do overlap and how many synergies it is possible to create pursuing these two urban strategies at the same time. After a deep analysis of the international literature about these two subjects, we examined the portfolio of the initiatives that are usually employed, and we compared it with the international indicators related to the green city performances. We outlined overlapping areas and reached conclusions on the convergence of smart and green urban policies.