As it influences the speed, frequency, and magnitude of innovation, the ability to recognize the value of new external knowledge, assimilate it, and apply it has rendered absorptive capacity arguably one of the most prominent constructs examined in organizational research. Even though a wealth of insights on absorptive capacity has been gained, the construct has suffered from inconsistent operationalizations, and has been refined and reconceptualized multiple times. Nevertheless, a large number of studies have examined the antecedents and outcomes of absorptive capacity. This chapter reviews the literature on absorptive capacity with the aim to set the coherent advancement of the construct. To that end, we provide an overview of how the definition of absorptive capacity has evolved, the levels of analysis involved and how studies have measured the construct, specifically by assessing refinements, extensions, and reconceptualizations of the construct. Given the inconsistent operationalizations, we review outcomes and antecedents heeded in prior research. Specifically, we distinguish between antecedents relating to the knowledge absorbed itself, the organization developing it, and the network organizations being operated in. Based on the review, we assess the progress made in the past two decades and seek to uncover central problems and prospects for future research.