Riga-Fede disease is a benign and ulcerative process that occurs as a result of repetitive trauma of the oral mucosal surfaces by the teeth. The authors describe here a case of a 40-year-old man in rescue therapy for advanced AIDS with a 2-month history of an ulcerated area on the dorsal surface of his tongue, which was histopathologically consistent with Riga-Fede disease. This case report is unique because it is the first time that this lesion has been reported in an AIDS patient, and Riga-Fede disease should be included in the differential diagnosis of a tongue ulcer in these populations.