The accessory cardiac bronchus is a rare congenital anomaly of the tracheobronchial tree that arises from the medial wall of the bronchus intermedius. This report documents the computed tomographic (CT) appearance of this anomaly. Six patients with this anomaly were identified. All six underwent CT; three underwent correlative bronchoscopy, and one had both bronchoscopic and surgical confirmation. In all six cases, a distinct airway could be identified originating from the medial wall of the bronchus intermedius. Associated lung parenchymal tissue was identified in four cases, while in three cases a discrete soft-tissue mass was seen, presumably representing vascularized bronchial or vestigial parenchymal tissue. In two cases, the lumen of the airway was filled with debris. Recognition of this anomaly is important, as associated clinical complications, including recurrent episodes of both infection and hemoptysis, may be anticipated in a small percentage of patients.