Diabetes mellitus is one of the most common problems challenging physicians in the 21st century. Type 2 diabetes mellitus accounts for at least 90% of all cases, which can be attributed in part to an aging population and the prevalence of obesity and sedentary lifestyles. In addition to the major impact on quality of life, diabetes accounts for a significant proportion of global healthcare expenditure, with the majority of costs attributable to treatment of its long-term complications. The principal cause of diabetes mortality is cardiovascular disease (CVD). There is a long period, prior to clinical detection of the disease, in which insulin resistance and hyperglycemia gradually worsen, and vascular complications develop. This article reviews the relationship between diabetes and the risk of CVD.