Although Candida esophagitis is one of the most common opportunistic infections in patients with acquired immunodeficiency syndrome (AIDS), there has been no systematic study of the endoscopic and pathologic manifestations of this disease. During a 53-month period, 141 patients with AIDS and Candida esophagitis were studied. All patients had the severity of esophagitis graded prospectively and esophageal mucosal biopsies performed. Tissue biopsies were evaluated for histologic evidence of ulceration, extent of candidiasis, and presence of viral cytopathic effect. Follow-up was obtained. There appeared to be a uniform endoscopic appearance; with increasing severity, the scattered mucosal plaques coalesced, resulting in circumferential disease and luminal impingement. The pathologic pattern of Candida esophagitis was homogenous. Plaque material was composed primarily of desquamated superficial hyperplastic hyperkeratotic squamous epithelium and inflammatory cells, with infiltration by fungal elements and bacteria consistent with superinfection. Although endoscopic and histopathologic ulcer was commonly seen in these patients (32%), only four patients had ulcer believed secondary to Candida esophagitis alone. In conclusion, in patients with AIDS, Candida esophagitis is a superficial mucosal infection resulting in characteristic endoscopic and histopathologic patterns.