Speed and accuracy are major considerations in triage in emergency field settings. Traditional physical examination techniques often are limited in detecting the true nature and full extent of internal visceral injuries, for which delayed recognition and treatment may lead to catastrophic results. Ultrasound has a well-established role in the rapid initial assessment of intra-abdominal pathologies, including trauma, and contemporary portable ultrasound machines are available for use in the field. This presentation will introduce the basic principles of diagnostic ultrasound and its use in emergency settings. Common clinical applications and pathologies and potential limitations and pitfalls also will be discussed with image illustrations.