Gestational diabetes mellitus (GDM) represents a heterogeneous group of metabolic disorders, which result in varying degrees of maternal hyperglycemia and pregnancy-associated risk. The frequency of GDM is rising globally and may also increase further as less-stringent criteria for the diagnosis are potentially adopted. The additional burden placed on the health care system by increasing cases of GDM requires consideration of diagnostic approaches and currently used treatment strategies. Debate continues to surround both the diagnosis and treatment of GDM despite several recent large-scale studies addressing these controversial issues. As many now have come to reassess their approach to the management of GDM, we provide information in this review to help guide this process. The goal for each health care practitioner should continue to be to provide optimum care for women discovered to have carbohydrate intolerance during pregnancy.