Nonobstetric disease requiring surgery may complicate pregnancy and jeopardize maternal and fetal well-being. Surgery may be safely done if the physician is aware of anatomic and physiologic alterations during gestation that necessitate an altered approach to diagnosis and management. Fetal exposure to all diagnostic and therapeutic agents should be minimized, particularly during organogenesis. However, the risk to the fetus of diagnostic irradiation is justifiable when information essential to maternal health is likely to be obtained. Furthermore, the broad range of available antibiotic, analgesic, and anesthetic agents provide the physician with options for treatment that have an acceptable degree of risk to fetal health. Anesthesia and surgery are tolerated considerably better by the fetus than is maternal hypotension, hypoxia, or sepsis. When an operative procedure is urgently or emergently indicated, pregnancy should not delay timely intervention.