We report three patients with esophageal wall thickening, incidentally found at CT, in whom further evaluation led to the diagnosis of diffuse esophageal spasm (DES). All cases showed smooth, symmetric, circumferential wall thickening of the distal two-thirds of the esophagus with normal periesophageal fat. No lung parenchymal abnormalities suggestive of aspiration were seen. DES, although uncommon, is another benign condition that should be included in the differential diagnosis of esophageal wall thickening detected by CT.