This article describes the important clinical events and decisions surrounding the reconstruction/unpacking portion of the staged celiotomy for trauma. Of 13,817 consecutive trauma admissions, 1175 received trauma celiotomies. Of these, 107 patients (9.1%) underwent staged celiotomy with abdominal packing. The authors examined medical records to identify and characterize: (1) indications and timing of reconstruction, (2) criteria for emergency return to the operating room, (3) complications after reconstruction, and (4) abdominal compartment syndrome (ACS). Fifty-eight patients (54.2%) survived to reconstruction, 43 (74.1%) survived to discharge; 9 patients (15.5%) were returned to the operating room for bleeding; 13 patients required multiple packing procedures. There were 117 complications; 8 patients had positive blood cultures, abdominal abscesses developed in 6 patients, and ACS developed in 16 patients. 1. Reconstruction should occur after temperature, coagulopathy, and acidosis are corrected, usually within 36 hours after the damage control procedure. 2. Emergent reoperation should occur in any normothermic patient with unabated bleeding (greater than 2 U packed cells/hr). 3. ACS occurs in 15% of patients and is characterized by high peak inspiratory pressure, CO2 retention, and oliguria. Lethal reperfusion syndrome is common but preventable.