Adrenal crises (AC) are life-threatening physiological disturbances that occur at a rate of 5-10/100 patient years in patients with adrenal insufficiency (AI). Despite their seriousness, there is a paucity of information on the epidemiology of AC events in the paediatric population specifically, as most investigations have focused on AI and ACs in adults. Improved surveillance of AC-related morbidity and mortality should improve the delineation of AC risk overall and among different subgroups of paediatric patients with AI. Valid incidence measures are essential for this purpose and also for the evaluation of interventions aimed at reducing adverse health outcomes from ACs. However, the absence of an agreed AC definition limits the potential benefit of research and surveillance in this area. While approaches to the treatment and prevention of ACs have much in common across the lifespan, there are important differences between children and adults with regards to the physiological, psychological, and social milieu in which these events occur. Education is considered to be an essential element of AC prevention but studies have shown that ACs occur even among well-educated patients, suggesting that new strategies may be needed. In this review, we examine the current knowledge regarding AC events in children with AI; assess the existing definitions of an AC and offer a new definition for use in research and the clinic; and suggest areas for further investigation that are aimed at reducing the incidence and health impact of ACs in the paediatric age group.