Incretin mimetics are a new class of pharmacological agents with multiple antihyperglycemic actions that mimic the actions of incretin hormones such as glucagon-like peptide (GLP)-1. Dipeptidyl peptidase (DPP-IV) inhibitors suppress the degradation of many peptides, including GLP-1, thereby extending their bioactivity. Several incretin mimetics and DPP-IV inhibitors are undergoing late-stage clinical trials for the treatment of type 2 diabetes. These agents appear to have multiple mechanisms of action, including some or all of the following: enhancement of glucose-dependent insulin secretion; suppression of inappropriately elevated glucagon secretion; slowing of gastric emptying; and decreased food intake (i.e. appetite suppression). Based on preliminary clinical data, incretin mimetics and DPP-IV inhibitors show potential for treating type 2 diabetes.