Diabetes mellitus had traditionally been considered disqualifying for flying duties. Increasingly, our understanding of both Type I and Type II diabetes permits identification of subgroups of diabetics with an acceptable aeromedical risk. A case is presented of a Canadian Forces pilot with Type I diabetes who continues on restricted flying duties. The pathophysiology of Type I and Type II diabetes is discussed, as well as aeromedical considerations for returning a diabetic to flying status. Within an envelope of defined geographic and operational flying limitations, diabetic aircrew may be safely and usefully returned to restricted flying duties.