Common risk factors for type 2 diabetes and cardiovascular disease are suspected because of the higher than expected prevalence of cardiovascular disease in individuals with newly diagnosed type 2 diabetes and in nondiabetic individuals with impaired glucose tolerance. Some of these risk factors may be genetic in origin. The risk of diabetes and cardiovascular disease may be linked through common pathways, including insulin resistance and/or inflammation. In this review, we describe the rationale for proposing these as common mechanisms affecting both diabetes and cardiovascular risk, and we then summarize the available evidence suggesting that common genes within these pathways have pleiotropic effects influencing susceptibility to both diseases.