The rapidly changing competitive landscape has challenged companies to become more entrepreneurial. Instead of falling prey to ever-changing market forces, some firms have shown great agility as they relentlessly introduce new products, services, and processes. These companies are driven by a continuous quest for opportunities that put their resources to better and more profitable use. The ability to orchestrate firms' resources and capabilities to realize opportunities is the topic of this dissertation. I refer to this ability as entrepreneurial capability (EC), which is defined as a firm's overall capacity to use its internal and external resources to continuously pursue opportunities. Therefore, the purpose of this dissertation is to provide a fine grained understanding of EC and examine its variability across five different contexts. Studying EC allows the examination of firm-level entrepreneurship by applying a capability perspective, which focuses on firms' orchestration of their resources and capabilities to develop opportunities. Opportunity development requires firms to collectively integrate their capabilities to transform them into actions. Successful enactment of opportunities is not about individual capabilities belonging to different functional areas but rather their reconfiguration, which links diverse resources and spurs new opportunities. Thus, this dissertation brings forward a focus on firms' capabilities and actions. This dissertation is designed as a compendium of publications and is comprised of seven chapters. Besides the introduction and conclusion, the five remaining chapters represent five individual papers that examine EC in multiple contexts. This reflects a high degree of diversity, which allows a close investigation of the manifestation of EC in several contexts. In turn, this brings focus on the differences among the type of opportunities pursued and their implications for integrating firms' capabilities.