DNA sequences closely related to herpesvirus-like sequences have been found in AIDS-associated Kaposi's sarcoma. Subsequent studies indicate that these DNA sequences may be consistently found in AIDS Kaposi's sarcoma and non-AIDS Kaposi's sarcoma from different geographic regions. Oral Kaposi's sarcoma is rare and the specificity of this viral DNA in oral Kaposi's sarcoma and in other oral neoplasms has not been examined. A total of 77 oral neoplasms, including 3 Kaposi's sarcoma specimens from 2 patients with AIDS, were analyzed by polymerase chain reaction for the presence of this herpesvirus-like DNA sequence with the 330-233 primers. All three specimens of oral AIDS-Kaposi's sarcoma from two patients were positive for this DNA sequence. All of the other intraoral lesions including hemangioma, pyogenic granuloma, and various types of epithelial neoplasms, however, had negative reactions. Our results further confirm that oral Kaposi's sarcoma appears to be associated with this herpesvirus-like DNA sequence.