Atherosclerosis is a complex pathological process that is accelerated in people with diabetes and accounts for a higher proportion of their total mortality than in the general population. It results from one or more established and/or ‘novel’ risk factors. Type 2 diabetes is characterized by obesity and insulin resistance (IR), and is frequently associated with hypertension and dyslipidaemia in combination with smoking rates similar to those of the general population. Other predictors of cardiovascular risk include microalbuminuria, elevated B-type natriuretic peptide, hypoadiponectinaemia, vitamin D deficiency and testosterone deficiency. Endothelial dysfunction is an important antecedent of many complications of diabetes; it has been noted in states of pre-diabetes and even in first-degree relatives. Early identification and prompt management of hyperglycaemia and other associated risk factors are important in securing a satisfactory long-term outcome at both individual and population levels. Relative cardiovascular risk is very high in type 1 diabetes, particularly in younger patients – an important area for future research.