This thesis explores the impacts of the dominant business model in the fashion industry, characterized by a trend of overproduction and overconsumption, and its negative effects on the environment and on society. A comprehensive literature review aims to assess the unsustainable practices of the fashion industry, the emerging role of the slow fashion movement, and the barriers individuals face in the transition to a more sustainable consumption. The thesis analyzes consumer purchase behavior and their interest in sustainability, focusing on behavioral economics and behavioral interventions designed to increase sustainable behavior and sustainable fashion consumption, specifically the deceptive practice of greenwashing and its influence on consumers’ choices is thoroughly examined. An online experiment is conducted to test participants’ responses to four different purchase scenarios, including the disclosure of information typically hidden by brands, greenwashed claims, real sustainable claims, and an intervention involving information provision, aimed to inform respondents about the existence of the greenwashing practices. Results highlight a significant impact of authentic sustainable claims on respondents’ decisions, guiding them towards sustainable choices. Directional results also suggest the effectiveness of greenwashed claims in influencing people decision-making, attracting them towards the “fake green” and affordable fast fashion garments. Additionally, directional results indicate that disclosing information about the existence of greenwashing increases individuals’ consideration and likelihood to choose the sustainable option, the same mechanism applies when disclosing the truth about the negative impacts of producing cheap fast fashion clothes. This study contributes valuable insight to the understanding of consumer behavior in the fashion sector, examining the impact of information disclosure, greenwashing, and interventions on customer decision-making. It introduces new implications and practical in-sights, addressing the complexities of the current shift towards a sustainable fashion consumption.