Glucagon-like peptide (GLP)-1 agonists and dipeptidyl peptidase-4 inhibitors are two classes of drugs that have been approved for treatment of Type 2 diabetes mellitus, based upon the glucose-lowering actions of the gastrointestinal hormone GLP-1. However, GLP-1 receptors are also present in cardiovascular tissues. Data from animal and in vitro studies suggest that GLP-1 may have cardioprotective effects and improve myocardial and endothelial dysfunction. Clinical data demonstrating cardiovascular effects are more limited, and there is some evidence that incretin-based therapies may be associated with improvements in cardiovascular risk factors. Large prospective cardiovascular outcome trials are underway to examine the cardiovascular safety of incretin-based therapies, and may reveal whether these agents are associated with any reduction in cardiovascular adverse events in patients with Type 2 diabetes mellitus.