The patient with acute abdominal pain presents the attending physician with a wide and varied gamut of diagnostic possibilities. Prompt and accurate diagnosis is essential for the proper care and management of these acutely ill patients. Diagnostic radiology is often an integral part of the emergent evaluation of these patients. This article focuses on some of the key plain-film findings in the patients suffering from acute abdominal pain of intestinal causes and reviews the radiologic evaluation of several major abdominal conditions such as acute appendicitis, diverticulitis, inflammatory bowel disease, bowel ischemia, and infarction.