Diabetes mellitus is a disease with a wide spectrum of severity and many potential complications if inadequately treated. Historically, diabetic pilots have been permanently disqualified from flying duties. This policy was based on the increased risk of sudden incapacitation in-flight due to hypoglycaemia and cardiovascular disease in diabetics. In recent decades, a shift in worldwide aeromedical policy has occurred. This has resulted in diabetic pilots in several countries, including the United States and Australia, being granted limited flying certification. These pilots are required to satisfy a number of stringent medical criteria to achieve this certification. Aeromedical policy must be based on an appropriate risk management strategy, taking into account all relevant issues. Australian guidelines for the certification of diabetic pilots are designed to limit certification to all but the most well-controlled, motivated, and well supervised diabetic with no disease-related complications.