Smart cities, developed as alternative to classical urbanism, are areas where information and communication technologies are used to make places more livable, sustainable and efficient. If a city offers solutions to problems related to governance, people, economy, mobility, environment and living issues, it can be defined as "smart city". The smartness of cities can be measured on these six basic axes. By analyzing the smartness of cities, evaluations can be made on the quality of life, health, public safety, environment and services. Hereby, appropriate measures can be taken against problems and strategies can be developed to increase the smartness of cities. This paper proposes a new decision making analysis to evaluate and compare the smartness of cities. For this aim, we considered the cities which are the candidates to be smart areas in Turkey. At this point, we applied multi-criteria decision-making (MCDM) analysis to evaluate criteria and alternatives in the decision process. We also utilized from fuzzy logic to model the uncertainty in the best way. Furthermore, we applied extended version of ordinary fuzzy sets which is named spherical fuzzy sets for the first time with QUALIFLEX method. Thus, one of the most comprehensive qualitative analyses ever made in the evaluation of smart cities is revealed and the usability of spherical fuzzy sets by MCDM methods is demonstrated. In addition, a sensitivity analysis was used to examine the robustness of the proposed method. As a result, a novel fuzzy decision-making approach has been proposed in the evaluation of smart cities.