The critical decisions in patients with thoracoabdominal trauma are establishing the need to explore either or both cavities and determining appropriate sequencing. The causes and patterns of management difficulties were analyzed in 82 consecutive patients with penetrating thoracoabdominal injuries. Nine thoracotomies (11%) and 16 laparotomies (22%) were negative, with the major causes being misleading chest tube outputs, bullet trajectories, and abdominal tenderness. Inappropriate sequencing occurred in 19 patients (23%), and 15% required reoperation within 24 hours. Pitfalls and misjudgments in management of penetrating thoracoabdominal injuries occur in distinct patterns. The unreliability of chest tube output and abdominal examination must be kept in mind, and intraoperative clues of ongoing hemorrhage outside the operative field must be sought.