PURPOSE: Oropharyngeal candidasis (thrush) is the most common opportunistic infection in individuals who are positive for the human immunodeficiency virus (HIV) and those who have progressed to AIDS. Itraconazole has a broad in vitro spectrum of activity, including a wide variety of Candida species. Our study determined the relative efficacy of a new oral solution formulation of itraconazole and fluconazole tablets in the treatment of oropharyngeal candidiasis. PATIENTS AND METHODS: This was a prospective randomized, third-party-blind, multicenter trial conducted at 12 centers in the United States. One hundred seventy-nine HIV-positive patients with mycologically documented oropharyngeal candidiasis were treated with itraconazole oral solution 200 mg/day for 7 or 14 days, or fluconazole tablets 100 mg/day for 14 days. Severity of disease was scored clinically before treatment and at clinical evaluations on days 3, 7, 14, 21, 35, and 42. Semiquantitative cultures of mouth washings were also obtained on these days. RESULTS: Both 14-day and 7-day regimens of itraconazole oral solution were equivalent to fluconazole for most efficacy parameters. The clinical response rate was 97% after 14 days of itraconazole and 87% after 14 days of fluconazole. Itraconazole oral solution given for 7 days was also equivalent to fluconazole treatment for 14 days. Approximately one half of patients in all three groups relapsed by 1 month after completion of treatment. There were few adverse reactions to either drug. CONCLUSION: Itraconazole oral solution is well tolerated and offers an alternative at least as effective as fluconazole in the treatment of oropharyngeal candidiasis.