Pulmonary artery pseudoaneurysm has been described as a complication of Swan-Ganz catheterization and right heart catheterization. Isolated cases of this condition occurring in blunt and penetrating chest trauma have been reported. In this communication, we describe the case of a patient with intracranial hemorrhage who required positive-pressure ventilation and in whom subsequent pneumothorax developed, necessitating tube thoracostomy. A persistent opacification of the lung field resulted in evaluation with computed chest tomography and color-flow Doppler ultrasonography. A pseudoaneurysm of the lingular segmental artery was identified and successfully obliterated by Gelfoam coil embolization.