Background: Every time sustainability has a more important role in the fashion industry and more consumers have higher environmental consciousness and look out for sustainable products in that area and companies that are genuinely sustainable. But the main problem is that lots of companies claim to be sustainable, but they are not and use the tactic of greenwashing, to attract consumers and trick them to purchase their products. Therefore, consumer education and awareness became essential to be able to avoid these misleading tactics implemented by the fast fashion firms.    Purpose: This study goal was to investigate the influence of customer knowledge of greenwashing on their purchase decisions and behaviour when it comes to environmentally friendly items, with a particular focus on the fast fashion sector.  This research endeavour aims to provide valuable insights into the challenges associated with promoting sustainable consumption and to propose strategies for increasing consumer engagement with genuinely environmentally friendly products through a comprehensive review of literature and empirical research.   Method: The investigation follows a deductive approach, and it uses both qualitative and quantitative methods to gather the information to resolve the research question. It uses focus groups as the main source of insights that are complemented by a survey.   Conclusion: Increasing the awareness of the consumer was enough to increase their purchase intention but not enough to convince them to make the change. The overall results add information on the findings of the literature review, but it would be interesting to add more information on our results, meaning that future research is needed to get more in-depth with these findings. In other words, have a more specific idea about consumer awareness on greenwashing and purchase intentions to sustainable products.