Although there are some instances of prior research on the relationship between attitude and purchase intention for environmentally sustainable products, literature is scant about mediating role of attitude on the relationship between environmental knowledge and purchase intention for environmentally sustainable products. Following the theory of planned behaviour, this study develops and tests a conceptual framework, which provides several insights. First, the attitude towards environmentally sustainable products mediates the relationship between environmental knowledge and purchase intention. Next, this mediated relationship is moderated by the environmental knowledge. Third, the subjective norm is not significantly related to the purchase intention - contrary to established findings - in a collectivistic culture considered in this study. And last but not the least, the direction of subjective norm as a moderator on relationship between environmental knowledge and attitude is not supported. The findings of this study offer some important guidance for marketing theory, retailing practices for environmentally sustainable products and public policy.