Abdominal ultrasound has become an extremely useful imaging modality in emergency medicine. Acute appendicitis can be diagnosed with ultrasound and is the preferred initial imaging modality by some clinicians for certain populations, such as in pregnant patients, to avoid ionizing radiation. Ultrasound can be a useful imaging modality for evaluation of abdominal wall hernias, such as ventral wall hernias, incisional hernias, spigelian hernias, femoral hernias, and inguinal hernias. The diseases of the GI tract that can be detected by ultrasound, but may be more appropriately detected by CT scan, are diverticulitis, bowel obstruction, and Crohn disease. Ultrasound imaging of the pancreas is not routinely sought in the ED, but rather more often done on an inpatient or outpatient basis for ultrasound-guided procedures. Ultrasound can be a challenging modality in obese patients and thus has some limitation in the evaluation of various intraabdominal diseases, such as appendicitis.