The fashion industry encompasses a wide range of activities related to the design, production, marketing and distribution of clothing, footwear, accessories and related products. In recent years, the disruptive social impact of the global fashion industry has been brought into the mainstream, challenging traditional fashion consumption and production practices, and the industry itself has become increasingly polarized between fast and slow fashion - two distinct approaches that cater to different consumer values and preferences. Slow or sustainable fashion is a broad term for clothing and behaviors that are in some way less harmful to people and/or the planet. Consumer behavior in the fashion industry therefore encompasses the intricate processes by which individuals select, purchase and use clothing and accessories, influenced by a mix of personal preferences, cultural trends and social dynamics. Today, the fashion sustainability movement is significantly influenced by Generation Z and Generation Y, each of whom exhibits unique characteristics and motivations that shape their purchasing behavior. This paper explored the impact of the sustainability trend in the fashion industry on consumer habits in Republic of Croatia, with an emphasis on generations Y and Z. Therefore, an empirical study was conducted, and a survey distributed via the Internet was used as a measuring instrument. The analysis of the research results concludes that although consumers who are more aware or concerned about the negative impacts of the fashion industry buy more sustainable clothing, in general, consumers' attitudes about the environmental harm of fashion are not aligned with their actual purchasing behavior. It was also found that consumers believe that generally more sustainable fashion brands have slightly higher price levels, however, sustainability itself is not the primary factor that shapes price perceptions, but rather some other factors such as brand reputation, availability and product quality. Testing the hypotheses established that among Croatian consumers there is a statistically significant difference between the attitude about the environmental harm of the fashion industry and the purchase of sustainable fashion items, and between the perception of the image of a fashion brand as sustainable and its price level.