To determine the sonographic features of Yersinia terminal ileitis, we analyzed the sonograms of eight patients with acute terminal ileitis. Bacteriologic or serologic confirmation of Yersinia enterocolitica infection was available in six patients. In the other two, the clinical course and radiologic findings were compatible with the diagnosis. Radiographs and endoscopy showed edematous mucosa with small elevations in the terminal ileum in all the patients. Sonograms showed thickening of the wall of the ileum in all eight patients and enlarged mesenteric lymph nodes in six patients. Although the number of the patients is small, our experience suggests that sonography can be useful for the detection of acute terminal ileitis caused by Yersinia.