Arthroscopy or “key hole” surgery has revolutionized joint surgery in both humans and horses. In horses it is routine to remove chip fractures, OCD lesions, lavage and evaluate infected joints and evaluate synovial structures in general (e.g. joints and tendon sheaths). The minimally invasive approach allows patients to recover quickly with minimal scarring and optimal return of joint function. This type of surgery is in a majority of cases performed under general anaesthesia but in selected cases the surgery can be performed in standing horses under intravenous sedation.