High-growth firms are at the forefront of academic research and policymaking in support of job creation. This article provides an overview of what we do and do not know about these firms. It is based on a systematic review of 159 papers published in higher-ranked academic journals from 1985 to 2022, supplemented by key papers published subsequently. The growing volume of research is channelled along what are becoming well-worn paths. It has entered a phase of diminishing returns before reaching any consensus on two pivotal questions: What are the antecedents of a high-growth episode, and why are these so short-lived? There is also growing scepticism among scholars on the feasibility and merit of having high-growth firms as a policy focus. It concludes by assessing the field and suggesting new research approaches and methods.