OBJECTIVE: To examine the clinical presentation, endoscopic features, laboratory diagnosis, and outcome of cytomegalovirus esophagitis in patients with the acquired immunodeficiency syndrome (AIDS). DESIGN: Retrospective review of endoscopy records and esophageal biopsy material from patients with AIDS during the 24-month period from 1986 to 1988. SETTING: Urban medical center, central receiving county hospital. PARTICIPANTS: Sixteen inpatients or outpatients seen by gastroenterology consultants at a single hospital. INTERVENTIONS: Endoscopy with multiple mucosal biopsies and viral culture of all esophageal mucosal lesions. Proven or suspected cyclomegalovirus disease was verified in patients using immunohistochemical antibody staining of mucosal biopsy specimens. MEASUREMENTS AND MAIN RESULTS: Odynophagia was the most prominent esophageal symptom, seen in 14 of 16 patients with cytomegalovirus esophagitis confirmed by immunohistochemical staining. Ulcerations of the esophagus were identified in all but 1 patient and typically appeared as large, solitary, shallow lesions. Routine hematoxylin and eosin staining of esophageal mucosal and submucosal specimens showed intranuclear inclusions in all patients, whereas cytomegalovirus culture was positive in only 8 of 14 patients. Cytomegalovirus esophagitis was associated with a poor long-term prognosis. CONCLUSION: Cytomegalovirus esophagitis in patients with AIDS is a well-defined entity with characteristic clinical symptoms and endoscopic findings, as well as histopathologic abnormalities.