We treated 20 patients thought to have mediastinal fibrosis secondary to Histoplasma capsulatum. All but 1 were symptomatic. The most common symptoms were dyspnea (8), hemoptysis (6), postobstructive pneumonia (5), and superior vena caval obstruction (2). Nine patients had severe stenosis of the trachea, carina, or main bronchus. Special stains identified Histoplasma capsulatum in surgical specimens in 9 patients. Surgical procedures were done for 18 of 20 patients (resection of subcarinal mass, 6; right middle and lower lobectomy, 5; carinal pneumonectomy, 4; esophagoplasty, 4; sleeve resection, 3 (with right main bronchus in 1, right lower and middle lobectomy in 1, and carina in 1); right upper lobectomy, 1; middle lobectomy, 1; and bronchoplasty of left main bronchus, 1. There were 4 deaths, 3 after complications of carinal pneumonectomy and 1 in a patient with tracheobronchial obstruction that could not be dilated. Two patients were treated with amphotericin and 4 with ketoconazole. Sclerosing mediastinitis secondary to histoplasmosis presents tremendous surgical challenges because of the intense fibrosis encountered. Bronchoplastic procedures are possible in spite of the intense fibrosis. High mortality rates after carinal resection may be encountered. The exact role of antifungal therapy is as yet undefined.