Instagram, a prominent social networking site, has become a popular online shopping platform among young people. In this study, we have attempted to understand what drives people to purchase in virtual stores on Instagram. Specifically, we built upon the integrative framework of trust and identified three groups of factors explaining consumer trust in Instagram stores: trustworthiness of Instagram stores (i.e., perceived benevolence, perceived integrity, and perceived competence), propensity to trust, and external environment (i.e., Key Opinion Leader (KOL) endorsement and peer customer endorsement). These factors are expected to influence consumer trust in Instagram stores, and trust in turn determines consumer intention to purchase. The model was empirically tested with 157 Instagram users. Perceived benevolence, perceived integrity, and KOL endorsement were found to be significant factors affecting consumer trust in Instagram stores, and trust was found to have a strong relationship with consumer purchase intention. The results of this study are expected to advance the trust literature in the context of social commerce and to offer practical guidelines to Instagram storeowners.