HIV-related oral candidiasis was investigated in 71 HIV-seropositive patients who received interviews, oral examinations and hematologic investigation. Diagnosis of candidiasis was based on clinical signs and examination of PAS-stained smears. The frequency of candidiasis was 24/71 (34%). The clinical presentations were pseudomembranous 8 (11%), erythematous 14 (20%), angular cheilitis 3 (4%). Twenty-six patients (37%) had candidiasis or were receiving antifungal treatment for recurrent pseudomembranous type. Twelve of 13 (92%) patients with AIDS and 14/58 (24%) without AIDS were affected. Bivariate analyses showed significant associations with AIDS, the use of zidovudine, low T4-count, xerostomia; marital status (sometime married), restricted performance status and age of greater than 35 yr. Multivariate logistic regression analysis showed that the presence of xerostomia was an independent and statistically significant predictor of HIV-related oral candidiasis. T4-count and restricted performance status were the second and third most important predictors.