PurposeThe present study aims to explore ethical consumption of Millennials and Generation Z and the effect of eWOM on their purchase intention.Design/methodology/approachA Structural Equation Model (SEM) was employed to test research hypotheses based on the Theory of Planned Behaviour (TPB), examining the effects of attitudes and subjective norms. Additionally, the study assessed the impact of product characteristics and consumer awareness of ethical characteristics on purchase intention and eWOM.FindingsResults reveal no significant differences between Millennials and Generation Z regarding purchase intention. However, Generation Z significantly drives the spread of eWOM. Notably, Generation Z's attitudes towards products from socially responsible and environmentally sustainable companies significantly influence eWOM creation, suggesting a potential new research direction.Research limitations/implicationsThis study is also subject to some limitations, which the researchers must point out and which may lead to further research. First, it should be emphasized that the study used a convenient sample, but the study is geographically limited in terms of its significance and the generations analyzed. For this reason, the generalization of the results should be done with caution. In addition, as the exogenous independent variables investigated in this study are limited to a number of different factors that influence the consumption of sustainable products, such as the company's reputation, the perceptual ability of the public to distinguish whether the actions of brands actually serve society or whether they are unrelated actions, as well as the personality and socio-cultural background of consumers can be included in future research. In addition, studies can be conducted to identify subgroups with different motivations among both Millennials and Generation Z and diagnose different market segments that could further confirm the findings.Practical implicationsBased on these findings, brands can develop their social network strategy by emphasizing the environmental and social attributes of their products, services, and benefits. It is also important to undertake initiatives linked to strong sustainability practices and information campaigns to form a positive attitude among consumers and strengthen their purchasing behavior. Particular attention should also be paid to the regular control of the effectiveness and impact of the messages to achieve the greatest public involvement.Social implicationsBrands must focus on developing successful strategies to strengthen employer branding through a positive work experience, the creation of jobs related to sustainability, the correct application of ESG criteria in all departments involved, the adaptation of training programs, and the corresponding promotion of all these practices that lead to positive eWOM to obtain a competitive advantage (Clementino and Perkins 2021).Originality/valueThis study contributes theoretically and practically to the understanding of ethical consumption. It provides valuable insights for brands to enhance their social network strategies by highlighting the environmental and social characteristics of their products. By emphasizing these practices, companies can effectively engage Millennials and Generation Z, leveraging their influence to promote ethical consumption and gain a competitive advantage in the market.