The present study applies asymmetric analysis and models complex antecedent conditions to identify shoppers with high purchase intentions to sustainable fashion products’ (SFPs) and high eWOM intention. The fuzzy-set qualitative comparative analysis (fsQCA) method was used to assess the cause-and effect process. The examination was based on information process, and decision making of consumers in two countries (China and Korea) was found to vary by nationality. Specifically, consumers in the two countries provided different responses on sustainable fashion change configuration, suggesting differences in the characteristics of sustainable and non-sustainable fashion consumers and sustainable fashion intentions. The results show that various casual recipes on sustainable fashion change the configuration and sustainable fashion intention on corners 1 and 4. Both Chinese and Korean consumers do not have several unique demographic and fashion expenditure configurations that characterize consumers with high intention to buy and eWOM intention favorable toward sustainable fashion. In the Chinese consumers’ data, computing with words (CWW) showed that young•married•low-income•low-education•low-fashionexpenditure cases (consumers) were lower on negation purchase and eWOM intentions (i.e., an accurate screening configuration identifying consumers high io non-sustainable fashion intentions). The results also help identify consumer characteristics of sustainable fashion consumers and non-sustainable fashion consumers. Specifically, the results of the fsQCA suggest dissimilar confirmation to achieve purchase intention and eWOM intention of sustainable fashion and provide meaningful academic and managerial implications. The results of the fuzzy-set qualitative comparative analysis also support and clarify the role of the theory of information process and the theory of reasoned action towards sustainable fashion.