The fashion industry is initiator of creativity and the development of market trends, and is characterized by seasonality, technological innovation and rapid change of trend. The task of retail is to select the appropriate activities of sales promotion to present customers fashion industry products in the most attractive way. The main goal of the master thesis is focused on the impact of sales promotion on the purchase of fashion assortment through the connection of sales instruments and the impact on purchasing decisions. Retailers in the fashion assortment stores use different combinations of promotional mix and sales promotion instruments to encourage consumers to buy despite their unique fashion styles. A better understanding of the observed topic requires a review of the Croatian and world retail market of the fashion assortment and its various comparisons. Different activities that improve sales do not affect the behavior of each customer equally, which will be the subject of research in the research part of the paper. Using the method of surveys on samples of Croatian consumers it will be analyzed the importance of certain instruments of sales promotion in the sale of fashion assortments and the creation of needs for its purchase.