Ultrasound (US) examination during graded compression was performed in 60 consecutive patients with clinical signs of acute appendicitis. In 25 (89%) of 28 patients with confirmed appendicitis, the inflamed appendix was visualized by US. Perforation was predictable in six of seven patients. In 32 patients without appendicitis, the appendix was not visualized. Graded-compression US is the examination of choice if there is doubt whether an appendectomy should be performed.