Cardiovascular disease remains the leading cause of death and disability in industrialized nations. The risk of cardiovascular disease is significantly reduced by lifestyle choices that promote cardiovascular health. Epidemiological data demonstrate that poor dietary choices, lack of exercise, smoking, obesity, stress, and pollution all increase cardiovascular risk. Poor habits and choices also have been shown to have adverse effects on vascular endothelial homeostasis leading to the development of endothelial dysfunction. Endothelial dysfunction includes broad regulatory changes leading to the expression of a vasoconstrictive, pro-thrombotic, and pro-inflammatory phenotype of the vascular endothelium. Interest in assessing lifestyle interventions as they relate to endothelial function has been encouraged by data demonstrating that measurements of endothelial function in easily accessible vascular beds such as the brachial artery correlate with risk for future cardiovascular events. Given the logistical difficulties and costs of performing large scale clinical trials assessing the ability of many lifestyle interventions designed to reduce cardiovascular risk, employing measures of endothelial function as a surrogate outcome for cardiovascular risk has allowed researchers to determine the biological plausibility of epidemiological data in this area with smaller studies. Newer study techniques, including genomic methodologies, now allow for better delineation of the mechanisms by which lifestyle choices affect the vascular endothelium and of the role of genetic variation in modifying these effects. This review discusses the effects of lifestyle choices on vascular endothelial function, the role and relevance of using studies that assess endothelial function in assessing cardiovascular risk, and future research directions in this area.