Many surgeons avoid the damage-control techniques of intrathoracic packing and temporary chest wall closure after thoracotomy for trauma because of concerns about packing's effects on intrathoracic pressure and infectious risks. We hypothesized that temporary chest closure with or without intrathoracic packing (TCC-P) as a method of thoracic damage control would yield higher than expected survival rates for trauma thoracotomy patients with metabolic exhaustion, whereas traditional definitive chest closure (DEF) would exhibit predicted survival rates. This was a retrospective cohort study by two urban Level I trauma centers on patients who (1) underwent emergent thoracotomy for trauma, (2) received ≥10 units (U) packed red blood cells and/or sustained a cardiac arrest before starting chest closure, and (3) survived to intensive care unit arrival. Demographic/physiologic data, chest closure method, and thoracic complications were gathered. Trauma injury severity scores (TRISS) were used to calculate survival probability for TCC-P and DEF. Nonparametric statistics were used for all comparisons. All values are expressed as medians and interquartile ranges (IQR). Sixty-one patients met inclusion criteria. Both TCC-P (n = 17) and DEF (n = 44) were severely injured (ISS=35 [IQR, 25-42] vs. 29 [IQR 19-45] and packed red blood cells = 16.5 U [IQR, 12.3-25.5 U] vs. 15 U [IQR, 11-23 U], respectively; p=ns). Patient demographics were similar except for the findings that the TCC-P cohort had higher rates of cardiac arrest before starting chest closure (TCC-P 82% vs. DEF 48%, p=0.04), significantly more severe abdominal injuries, and less severe head injuries than the DEF group. No significant differences were observed in survival of the overall samples (TCC-P=47% vs. DEF=57%), nor for observed:expected (O:E) survival ratio in 13 patients with TCC-P and 30 with DEF meeting criteria for TRISS calculation (TCC-P O:E, 46%:39%; DEF O:E, 53%:57%). No significant differences were found for TCC-P and DEF thoracic infectious (24% vs. 25%) or hemorrhagic (18% vs. 14%) complications. Surprisingly, peak inspiratory pressures on intensive care unit arrival were markedly better after TCC-P (20 cm H2O [IQR, 18-31 cm H2O]) than after DEF (32.5 cm H2O [IQR, 28-37.5 cm H2O], p=0.003). Concerns about TCC-P are not borne out as thoracic infection rates are unaffected and peak pressures are actually lower, possibly due to greater pleural volume from an open chest wall and skin-only closure. However, no significant survival benefit was seen with TCC-P.