The medical records of 114 consecutive HIV-infected patients with oropharyngeal and esophageal candidiasis, in whom esophagoscopy was performed, were reviewed. Esophageal candidiasis and isolated oral candidiasis were found in 75% and 25% of patients, respectively. Esophageal candidiasis was the AIDS-defining illness in 65 patients and dysphagia was the commonest symptom, but asymptomatic Candida esophagitis was observed in 43% of them. Symptoms were present in six patients with oropharyngeal candidiasis; three of them had a normal esophagoscopy and the other three had acute nonfungal esophagitis. Invasive fungal esophagitis was confirmed by biopsy in 47/74 patients (64%). The patients with esophageal candidiasis had lower CD4+ cell counts (129/microliter) and CD4:CD8 ratios (0.23) than those with oropharyngeal candidiasis (CD4 179/microliter; CD4:CD8 0.35). Thirty-six patients with esophageal candidiasis were treated with fluconazole, 100 mg/daily, for 28 days, and another 34 patients received the same dose for 10 days. A similar efficacy was seen in both regimens, but a higher incidence of oropharyngeal fungal colonization and liver dysfunction was observed in the longer therapy (p < 0.001). We conclude that asymptomatic C. esophagitis is common in HIV-infected patients. Patients with oropharyngeal candidiasis may complain of esophageal symptoms; it could be due to superficial C. infection or another not-identified opportunistic infection. More severe immunologic impairment was required to develop esophageal candidiasis than oropharyngeal candidiasis. A short course of 10 days of fluconazole therapy could be the standard regimen for the treatment of C. esophagitis in AIDS.