Though reportedly aware, the importance of sustainability is not reflected in consumers’ consumption behavior. Existing research excludes both the concept of mindset as a driver for sustainable consumption and the diminishing effect of stress on this relationship. We close this gap by examining how a growth mindset indirectly affects consumers’ sustainable purchase decisions, mediated by the preference for sustainable products, and the influence of technostress in an experimental online shopping scenario. Results based on 121 participants show a positive indirect effect of growth mindset on consumers’ sustainable product choice, mediated by their general preference for sustainable products, while technostress has a negative moderating effect on the relationship between preference for and choice of sustainable products. Our study contributes to the ecommerce and consumer psychology literature and extends research by showing how external influences disrupt the purchase decision of consumers who are usually inclined towards purchasing sustainable products under non-invasive conditions.