Aplastic anaemia is a rare, previously fatal condition with a significantly improved survival rate owing to advances in understanding of the pathophysiology and improved treatment strategies including haematopoietic stem cell transplantation. Although a rare condition, aplastic anaemia continues to present a high burden for affected patients, their families and the health system due to the prolonged course of disease often associated with high morbidity and the uncertainty regarding clinical outcome. Modern molecular and genetic techniques including next-generation sequencing have contributed to a better understanding of this heterogeneous group of conditions, albeit at a cost of increased complexity of clinical decision-making regarding prognosis and choice of treatment for individual patients. Here we present a concise and comprehensive review of aplastic anaemia and closely related conditions based on extensive literature review and long-standing clinical experience. The review takes the reader across the complex pathophysiology consisting of three main causative mechanisms of bone marrow destruction resulting in aplastic anaemia: direct injury, immune mediated and bone marrow failure related including inherited and clonal disorders. A comprehensive diagnostic algorithm is presented and an up-to-date therapeutic approach to acquired immune aplastic anaemia, the most represented type of aplastic anaemia, is described. Overall, the aim of the review is to provide paediatricians with an update of this rare, heterogeneous and continuously evolving condition.