Sonographic findings in eight patients with Crohn's disease were evaluated with high-resolution ultrasound. In all patients, the diseased bowel wall was clearly thickened, ranging from 6 to 14 mm thick (mean: 9 mm). The layered structure of the bowel wall was generally indistinct. Especially in patients with serious intestinal obstruction due to fibrosis, wall stratification was completely lost and the intestinal wall appeared to be uniformly hypoechoic. Ruggedness along the inner and outer margins of the bowel wall was another element of the findings. Ultrasound cannot substitute for barium studies or colonoscopies; however, it is a safe and useful alternative method in the diagnosis of Crohn's disease.