This paper examines the antecedents of millennials' organic food purchasing. A conceptual framework, based on product characteristics, and consumers' concerns and consciousness, is proposed. Data collection was conducted through a survey in two culturally and socioeconomically distinct countries (Brazil vs. Spain) to increase the robustness and generalizability of the results. The results show that product characteristics and consumer concerns improve millennials' health consciousness and increase their social consciousness, which, in turn, increase their willingness to pay a price premium and their purchase frequency of organic foods. The findings show that the proposed model has high validity, with only one significant difference between the two countries. Theoretical contributions and managerial implications are discussed.