Attention-deficit/hyperactivity disorder is a problematic diagnosis in the context of aeromedical certification. Certain characteristics of the disorder such as impaired attention potentially affect the safe conduct of flying. Pharmacological treatment with stimulants also has issues surrounding short half-lives and effects on the recognition of fatigue. This article gives a broad overview of the issues involved and provides certification guidelines as adopted in the Australian Civil Aviation Safety Authority which may be helpful if adopted by other certification bodies.