We reviewed 144 consecutive patients with flail chest and/or pulmonary contusion between 1979 and 1984. The purpose was to analyze the factors adversely affecting morbidity and mortality. There were 97 males and 47 females, with an average age of 40 years ± 18 S.D. (range, 2-83). Seventy-five per cent of the injuries were caused by motor vehicle accidents, with the remainder due to falls (17%), cardiopulmonary resuscitation (4%), altercations (2%), or falling objects (2%). The Injury Severity Score (ISS) averaged 32 ± 14 S.D. in all survivors versus 60 ± 14 S.D. in those who died. Eighty-three patients (58%) required mechanical ventilation. Thirty-six patients died (25%). Isolated pulmonary contusion or flail chest had a mortality of 16% each. However, the mortality more than doubled when there was a combined pulmonary contusion and flail chest (42%). More than half of all deaths were directly attributed to central nervous system injuries with another third due to massive hemorrhage. Factors that were associated with a higher morbidity and mortality included severe associated thoracic injuries, a high ISS, the presence of shock, falls from heights, and the combination of pulmonary contusion and flail chest.