This study explores if there is a convergence between the concepts of fashion and eco-friendliness in consumer perception of a fashion brand. We assume that increased eco-friendly perception will influence the brand image positively, with this impact being much higher for luxury than for high and fast fashion brands. The hypotheses are tested using data collected from Twitter. We analyzed the fashion clothing brands with the highest number of followers on the Socialbakers list and applied a novel social network mining methodology that allows measuring the relationship between each brand and two perceptual attributes (fashion and eco-friendliness). The method is based on attribute exemplars—that is, Twitter accounts that represent a perceptual attribute. Our exemplars catalyze social media conversations on fashion (identified in our research by the keywords “fashion,” “glamour,” and “style”) and eco-friendliness (keywords “environment” and “ethical business”). Based on social network analysis theory, we computed a similarity function between the followers of the exemplars and those of the brand. The results suggest that there is a correlation between the fashion and the eco-friendliness perceptual attributes of a brand; however, this correlation is far stronger for luxury brands than for high and fast fashion brands. The difference in the correlations confirms the recent tendency of fashion luxury brand to increasingly consider treating environmental issues as part of their core business and not just as added value to the brand’s offer. •Eco-friendliness is becoming a fundamental component of the value proposition of fashion brands.•There is strong correlation between the fashion and the eco-friendliness perceptual attributes of luxury brands.•Consumers are more sensitive to fashion brands’ environmental rather than ethical business practices.