Myasthenia gravis is an autoimmune condition where antibodies form against the acetylcholine receptors at the neuromuscular junction, eventually causing damage to the motor end plate. The clinical features include muscle fatigability as well as ocular, bulbar, and limb weakness, which can have implications on the role of a pilot or air traffic controller. This retrospective study reviewed the United Kingdom Civil Aviation Authority (UK CAA) experience of myasthenia gravis. A search of the United Kingdom Civil Aviation Authority medical records database from 1990 to 2016 identified 11 individuals with a diagnosis of myasthenia gravis. Data were extracted for the class of medical certificate, age at diagnosis, symptoms, acetylcholine receptor antibody status, treatment, the time from diagnosis to loss of medical certification, and the reasons for loss of certification. There were two Class 1 certificate holders (for professional flying) and six Class 2 certificate holders (for private pilot flying) and three air traffic controllers. The mean and median ages at diagnosis were 53 and 57 yr, respectively, with a range of 28-67 yr. The mean and median intervals from diagnosis to loss of certification were 22 and 11 mo, respectively, with a range of 0 to 108 mo. The aeromedical implications of myasthenia gravis, including complications, types of treatment, and functional impact, are considered. A policy for medical certification following a diagnosis of myasthenia gravis is proposed.Jagathesan T, O'Brien MD. Myasthenia gravis and its aeromedical implications. Aerosp Med Hum Perform. 2017; 88(1):30-33.