Background: Consumers are today valuing sustaible brands and products, and green advertising has become an important part of marketing. Sometimes brand do not live up to their green claims and perform what is known as greenwashing. Prior research has concluded that the act of greenwashing hurts consumers' attitude towards brands and this research further explores the effect of greenwashing on attitude formation. Purpose: The purpose of this paper is to explore how greenwashing affects consumers' attitude formation towards brands.  Methodology: For this research, a qualitative research approach with an exploratory nature was used. When gathering the empirical data, semi-structured interviews were conducted. The questions were designed to be open-ended in order to gain in-depth information. Before conducting the interviews, a pilot test through two semi-structured interviews was conducted in order to identify if there were any questions that could be improved. For the main study, seven semi-structured interviews were conducted with participants within generation Z, both men and women.  Findings: The key findings is that greenwashing only has a short-term effect on attitude formation which resulted in consumers avoiding the accused brand. The participants' attitude formation changed from the experiential hierarchy to the standard learning hierarchy when greenwashing was discovered.  Conclusion: Cognition had the largest impact on attitude formation as greenwashing was discovered, since it created negative feelings towards the brand. However, the acccusations were seen to be easily forgotten and consumers would go back to old behaviour (experiential hierarchy) in the long-term.