Diabetes mellitus is a disabling, chronic cardiovascular and medical disease with a tremendous health, social and economic burden in our ageing communities. It has a prevalence of 10% to 30% in people older than 65 years of age, and more than half of all subjects with diabetes in the United States are older than 60 years of age. The main impact of diabetes in older adults stems from its effect on function, both physical and cognitive, that finally impairs their quality of life, although the impact on survival is modest. Frailty has emerged during the past 2 decades as the most powerful predictor of disability and other adverse outcomes, including mortality, disability and institutionalization in older adults. In this article we explore the relationship between diabetes and frailty, and we recognize that they are intimately related chronic medical conditions that result in huge societal and personal health burdens.