AIDS-associated Kaposi sarcoma (KS) is the most common HIV-associated neoplasm. Disseminated Kaposi sarcoma became rare with the application of antiretroviral therapy. Oral AIDS-associated KS has prognostic relevance, indicating higher mortality than those with cutaneous lesions only. In this study, we reported a 40-year-old man presented with ulcerated violaceous plaques on his hard palate. Similar lesion can be observed on his left groin and anus, as well as on esophagus and gastric fundus under upper gastrointestinal endoscopy. Histological examination accorded with KS. After five cycles of doxorubicin, his oral, skin and esophagus lesions regressed considerably.