Tuberculosis is endemic in Brazil, especially in Rio de Janeiro. This paper describes a case of tuberculosis of the larynx treated at a university hospital and discusses the difficulties encountered in diagnosing it. CASE REPORT: A 65-year-old, white woman working as a housekeeper, presented with progressive dysphonia, odynophagia, dysphagia to solids, dyspnea, and nocturnal cough for 3 months; she had lost 6 kg weight over the same period. She denied having any fever but admitted to smoking about 90 packs of cigarettes a year; she also gave a history of hypertension and diabetes. Clinical otorhinolaryngological examination was normal. Video laryngoscopy showed significant Reinke's edema, along with a supraglottic lesion that partially obstructed the airway. Chest radiography done as a part of preoperative check-up showed atelectasis. Tuberculin testing with PPD yielded a strongly positive reaction, so the patient was started on anti-tuberculosis treatment. Video laryngoscopy was repeated after 3 months of treatment; the only pathological finding was a polypoid lesion in the right vocal cord. Therefore, we assumed that the lesion that obstructed the airway was not the polyp, but the initially detected supraglottic lesion that had disappeared after anti-tuberculosis treatment. CONCLUSION: Tuberculosis is an important condition in the differential diagnosis of laryngeal mass lesions. Primary laryngeal tuberculosis presents a diagnostic challenge to the otorhinolaryngologist, because its signs and symptoms resemble those of malignant diseases, as seen in the present case.