Sonography should be considered the primary imaging modality in patients who present with gynecologic or obstetric emergencies. Transvesicle scans have proved to be sensitive tests for studying a wide variety of gynecologic conditions, and the recent addition of high-resolution transvaginal probes has further enhanced the diagnostic ability of ultrasound. Pelvic pain is the most common cause of emergency department visits in girls and women, and the differential diagnosis is broad. Many gynecologic emergencies, such as pelvic inflammatory disease, hemorrhage of an ovarian cyst, and ovarian torsion, have suggestive sonographic features. Pregnant patients who have acute complications such as ectopic gestation, placental abruption, and rarely, uterine rupture may also show diagnostic signs. Sonography is also effective in evaluating postpartum complications and in diagnosing conditions such as appendicitis and diverticulitis, which may mimic gynecologic emergencies.