In this article, we explore how new capabilities emerge and solidify in new ventures that are faced with fundamental uncertainty from their environment. To do so, we draw from the organizational and entrepreneurial literature on cognition and capabilities. Using initial qualitative evidence from a multi-firm study in the context of new venture internationalization, we develop a cognition-based model of capability emergence in new ventures. Our findings extend the capability development and learning implications of internationalization to the fundamental character of organizing processes in start-ups. Moreover, we derive avenues for future entrepreneurship research on the origins and evolution of capabilities in new ventures.