Endoscopic experience in patients with acquired immunodeficiency syndrome (AIDS) has rarely been reported in Taiwan. We present our experience in 9 AIDS patients (8 male and 1 female, age from 26 to 63 years) with 12 examinations. The risk factor of these patients were bisexual in 3, homosexual in 2, hemophilia in 1, drug abuse in 1, and paid-sex in 2. Odynophagia or dysphagia was the major complaints. Oral ulcers or/and thrush were noted in 8 patients. Endoscopic findings included negative (6/12), candidiasis (3/12), erosions (1/12), ulcers (1/12) and ulcer scar (1/12) in esophagus; negative (8/12), gastritis (1/12), erosions (1/12), ulcers (1/12) and Kaposi's sarcoma (1/12) in stomach; and negative (11/12) and duodenitis (1/12) in duodenum. Patients with esophageal candidiasis always had oral thrush. Dysphagia was highly correlated with positive endoscopic findings in esophagus. It is important for an endoscopist to identify clinical symptoms and to examine patient's oral cavity before an endoscopic examination. The endoscopist must keep himself from being infected by exposure to contaminated blood and secretion and avoid dissemination of this horrible disease by undisinfected instruments.