The chapter investigates the synergy between luxury brands and slow fashion since both share several connections, primarily revolving around their focus on quality, exclusivity and sustainability. The synergy between slow fashion and luxury fashion brands lies in their shared commitment to producing high-quality, sustainable and ethically made clothing that provides long-term value to consumers. Even though not all luxury fashion brands fully adhere to slow fashion principles, and the extent of their commitment varies, increased pressures such as environmental regulations, brand reputation and consumer demand for sustainability may encourage more luxury fashion brands to adhere to these principles. The chapter investigates whether there is congruency between Gen Z consumers’ sustainability values and their purchase behaviour and how it can potentially affect their attitudes towards sustainable luxury fashion brands. The empirical study was carried out in Czechia and Cyprus and revealed that although Gen Zers are the biggest advocates for sustainable fashion, they are also fast fashion consumers. Thus, the study explored this attitude-behaviour gap and the incongruency between sustainability values and consumer behaviour.