The treatment of gynecologic and other infections in obstetric patients involves consideration of the physiologic changes of pregnancy, the clinical implications of the infection for the patient as well as the fetus, and the safety of antimicrobials available for therapy. This article highlights the treatment of infections of the vagina, uterus, and urinary tract, with a focus on how therapy changes in obstetric patients. In addition, the emergency department management of other clinically important infections in pregnancy, such as those caused by the human immunodeficiency virus, influenza viruses, methicillin-resistant Staphylococcus aureus, Parvovirus, Listeria, and others is reviewed.