A 15-yr-old male hemophiliac developed the acquired immune deficiency syndrome (AIDS). His terminal illness was characterized by rapidly progressive respiratory failure with intermittent wheezing, nonresponsive to bronchodilator and steroid therapy. Postmortem examination revealed a pseudomembrane covering the mucosa of the lower trachea and bronchi of both lungs. This pseudomembrane was composed predominantly of fungal hyphae speciated as Aspergillus niger. There was widespread transmural necrotizing bronchitis and fungal invasion that extended to involve a narrow zone of peribronchial tissues. The intervening lung parenchyma was free of fungal disease. This unique form of bronchitis is a distinct variant of invasive aspergillosis and merits recognition because of its clinical and prognostic implications.