Four patients with herpetic esophagitis were examined. In three of them, the presenting symptom was odynophagia. Early in the course of herpetic esophagitis, shallow round and oval ulcers were seen on barium esophagograms. Later, the ulcers filled with fibrinous exudate, forming nodular plaques that projected into the esophageal lumen. Although these findings are diagnostic of esophagitis, they are not specific for a herpes virus infection. The definitive diagnosis must be established by histologic examination, which demonstrates the cytopathic effect of the herpes virus infection within the squamous epithelium.