Weaning represents one of the most stressful events in the life of a horse, and may have long-term impacts on behaviour. There are a range of approaches used to wean foals from mares, including abrupt and progressive separation methods. There is currently a lack of consensus on how stress and impact are measured. To conduct a scoping review to identify and chart measures of weaning-related stress on the mare and foal. Scoping review. The scoping review was conducted using the PRISMA extension for scoping reviews. Systematic searches were conducted in three scientific databases (CAB abstracts, Medline and Embase). The title, abstract and full text of retrieved studies were reviewed against inclusion and exclusion criteria. Publications that remained after full text review were analysed. Data on study design, population characteristics, weaning method and health and behavioural outcomes were extracted and charted. A total of 366 publications were identified; 22 were retained for inclusion and charting. Eighteen studies reported behavioural measures, four only reported physiological measures and 12/22 studies used a combination of both. Fifteen studies analysed foal behaviour only (15/22), six analysed foals with their dams and one analysed the mare only. Duration of most studies (19/22) was a maximum of 12 months post weaning; three studies continued measurements until the foal age was 3-4 years old. Limited number of studies available for analysis. There is significant variation in the current evidence around weaning-related impacts in the mare and foal. This includes variation in how weaning methods and management of mares and foals are described, and very limited research evaluating long-term impacts, or the impact on the mare. This scoping review makes recommendations on how to improve the future evidence base.