Modern cities are developing dynamically in search of ever newer concepts of management. One of them, developed in Poland since the 1990s, is the concept of the marketing management of the city, which is based on the marketing mix concept. The city authorities also look for new sources of the competitive advantage (this is how the concept of slow city management was born). At the same time, in addition to competition, there is a desire for cooperation between cities, manifested by the development of the Citt?slow city network. The study identifies the marketing mix instruments of cities which are used by Polish cities after they joined the Citt?slow network. The method employed was a questionnaire survey, which was sent to 26 Polish Citt?slow member cities in 2017. It was observed that the greatest changes occur in the product strategies under which cities are obliged to develop these urban sub-products that are necessary for the city to function in accordance with the slow city philosophy. As part of promotional efforts, PR activities should be emphasised, whose aim is to create the image of a slow city. The “hospitality” of the city and openness to contacts with the external environment has also increased.