Past studies have shown that the flow of knowledge from incumbent firms is associated with the creation of startups and their subsequent performance. While much research has focused on the mechanisms of how incumbent-to-startup knowledge transfer takes place, such as entrepreneurs pursuing opportunities that their previous employers do not want to pursue, we explore with detailed qualitative analysis of six private startups in the Chinese synthetic-dye industry what type of knowledge actually flows and what type is more important for the long-term success of startups. We discover eight types of knowledge that flow from incumbents to new firms during the foundation of startups. Abstracting these eight types of knowledge into two general categories of functional knowledge and strategic knowledge, we find the reception of strategic (not functional) knowledge shapes the long-term competitiveness of surviving startups. Receiving technical knowledge – one type of functional knowledge – during the founding period is necessary for startups’ short-term survival but insufficient for long-term success. Our findings show that the performance implications of initial knowledge flows from incumbents hinge on the type of knowledge, contributing to a more explicit explanation of how incumbent-to-startup knowledge flows affect entrepreneurial performance.