BACKGROUND: Kaposi sarcoma is a well-known vascular tumor first described by Moriz Kaposi in 1872. Oral involvement is seen as an AIDS-related malignant neoplasm but is rarely described in HIV-negative and non-immunosuppressed individuals. CASE: We report a case of oral Kaposi sarcoma in a 75- year-old, HIV-negative woman. Diagnosis was achieved according to clinical, histopathological and positive polymerase chain reaction for human herpes virus 8. The tumor was surgically excised and no recurrence was detected in the following 6 months. CONCLUSION: Oral Kaposi sarcoma is rare in HIVnegative patients and is associated with HHV-8 infection. Lesions are usually solitary and can be treated surgically. It should be included in the differential diagnoses of oral lesions that are clinically suspicious and resistant to therapy. © Science Printers and Publishers, Inc.