Percutaneous catheter drainage is a standard therapy for management of selected intra-abdominal abscesses. We describe three patients in whom this technique caused complicated thoracic empyemas. All patients required thoracotomy for decortication despite initial thoracostomy tube drainage. In each case, the percutaneously placed drainage catheter was found traversing the costophrenic angle, leading to direct communication between the pleural space and the abscess cavity. Review of the anatomic relationships of the inferior pleural margin to the lower ribs may help prevent this technical error.