While diabetes mellitus types 1 and 2 used to be distinguished largely by age at onset, in the past decade there has been an increase in the number of children presenting with diabetes that can be controlled with oral medications. This has lead to these children being diagnosed with type 2 diabetes mellitus despite their young age. This chapter offers an overview of presenting features, pathophysiology, treatment and prognosis of this disorder in the adolescent patient. Additionally, it offers information regarding the relationship between increasing childhood obesity and a rise in the reported cases of diabetes in children. Appropriate screening and laboratory tests and their results are explained, and the pros and cons of both pharmacologic and non-pharmacologic therapies are discussed. Some complications of diabetes in the developing adolescent differ from those adults will face, and the well-known complications of diabetes (hyperlipidemia, hypertension) must be addressed in a population that is not normally screened for these health concerns. It is hoped that by educating physicians to the potential for this disorder in their adolescent patients, long-term complications can be reduced and advanced sequelae of vascular and neurologic problems can possibly be avoided altogether.