INTRODUCTION: Kaposi's sarcoma is a multifocal malignant systemic disease that originates in the vascular endothelium with a variable clinical course. The most common manifestation of this disease is the appearance of skin lesions, but the mucous membranes, lymphatic system, and viscera, in particular the lungs and digestive tract, can also be affected. The final diagnosis is made by biopsy, and treatment depends on the size and location of the lesions as well as the patient's general condition. In HIV patients, spontaneous regression of the lesions usually occurs within 3-6 months with antiretroviral therapy. In severe cases, chemotherapy can be used as an adjuvant therapy. OBJECTIVE: To report a case of Kaposi's sarcoma in the oral cavity and larynx in an HIV patient that progressed to tracheostomy. CASE REPORT: The patient, a 33-year-old white HIV-positive man, receiving highly active antiretroviral therapy (HAART) (lamivudine, tenofovir, and efavirenz) treatment presented at the otolaryngology service of Santa Casa da Misericórdia - Rio de Janeiro with macules and papules on the upper and lower limbs as well as red-purple nodular lesions on the palate and larynx. There had been rapid evolution of these lesions and resulting dyspnea on mild exertion along with intense odynophagia. The patient developed respiratory failure and underwent emergency tracheostomy. He was started on paclitaxel chemotherapy, which resulted in a dramatic reduction of lesions in the larynx. This allowed subsequent removal of the tracheostomy. CONCLUSION: Otolaryngologists should stay alert for mucosal lesions in HIV-positive patients, especially Kaposi's sarcoma.