Upper airway obstruction secondary to a carotid mycotic aneurysm has not been previously reported. We describe a patient with a mycotic aneurysm associated with a deep neck infection and presenting with acute tracheal obstruction. Recognition of this condition is important to avoid inadvertent rupture of the aneurysm in the course of diagnostic aspiration or surgical drainage. Physical findings, including a pulsating mass and an arterial bruit, in addition to appropriate imaging studies, may be helpful in suggesting the diagnosis. In particular, both neck and chest contrast-enhanced computed tomography scans may give important clues to the presence of a vascular lesion. In a patient with an infected neck mass and tracheal compression, a common carotid mycotic aneurysm should be considered in the differential diagnosis.