When pharmacologic therapy is required, oral antidiabetic agents have been almost universally endorsed as first line drugs in the treatment of gestational diabetes mellitus (GDM) based on well-designed studies that have found no association between these agents and congenital malformations. These agents have an efficacy comparable with insulin in their ability to facilitate achievement of targeted levels of glycemic control on all GDM severity levels and in obese patients. Therefore, level of glycemic control achieved, not the mode of therapy is the key to improving outcomes in GDM.