Thyroid disorders are often ubiquitous and insidious in their presentation. They have been implicated in a broad spectrum of reproductive disorders ranging from abnormal sexual development to menstrual irregularities and infertility. If pregnancy occurs in a patient with thyroid disease, the physician must ensure that therapeutic measures instituted to restore the health of the mother do not adversely affect the developing fetus. This review examines the role of thyroid disease in disorders confronting the obstetrician/gynecologist and provides a theoretical framework upon which to base practical management decisions.