Diabetes comprises many syndromes whose only common feature is a high blood glucose level. Some are entirely genetic, some partially so, and others not at all. Perhaps the most important advance in the past 10 years is proof that insulin dependent diabetes is genetically different from the insulin independent form. Most progress has been made in unraveling the etiology of insulin dependent diabetes, although more information is needed before the mode of inheritance is finally settled. The last few years have produced a plethora of new facts about insulin dependent diabetes mellitus, providing geneticists, clinicians, and epidemiologists with the fascinating challenge of a disease with an apparently genetic susceptibility to external (environmental) triggers. Little progress has been made in the field of insulin independent diabetes, and one might safely predict that the diabetic syndrome will still produce some nightmares for researchers who take up the challenge of trying to unravel its various etiologies and methods of inheritance.