Idiopathic esophageal ulcerations (IEUs) associated with human immunodeficiency virus (HIV) infection are now recognized as an important cause of esophageal disease in this population. Limited radiographic and endoscopic reports have almost uniformly described these lesions as solitary and giant. Over a 28-month period, we identified 68 IEUs endoscopically in 23 patients. Most patients had long-standing HIV infection and a low CD4(+) lymphocyte count. Multiple ulcers were identified in 57% of endoscopies. Giant ulcers were seen in one-third, with 37% ≤ 1 cm in greatest dimension. Most of the lesions were in the mid- to distal esophagus. The ulcers were characterized as either shallow or intermediate in depth in 53%, with a deep ulcer in 7%. A “heaped-up” appearance of the ulcer was identified in 40%. An esophageal mucosal bridge(s) was seen in two patients. In contrast to previous reports, IEUs are variable endoscopically in number, size, and appearance. Given this lack of uniformity in appearance, which may mimic other causes of esophageal ulceration, all HIV-infected patients with an esophageal ulceration should undergo endoscopy with biopsy to obtain a definitive diagnosis. © 1993 Raven Press, Ltd., New York.