['The 80-hour workweek limitation for surgical residents is associated with an increase in mortality and complication rates among adult trauma surgical patients.', 'Retrospective cohort study.', 'Academic level I trauma center.', 'Trauma patients admitted before and after the 80-hour workweek limitation.', 'We compared death and complication rates for adult trauma patients admitted during a 24-month period before (2001-2003) and a 24-month period after (2004-2006) implementation of the 80-hour workweek at our institution. Relative risk and its 95% confidence intervals were examined.', 'Patient care outcomes included preventable and nonpreventable complications and deaths.', 'The patient populations from the 2 time periods were clinically similar. No significant differences were found in the total and the preventable death rates. The time period after the 80-hour workweek mandate had a significantly higher total complication rate (5.64% vs 7.28%; relative risk, 1.29; 95% confidence interval, 1.15-1.45; P < .001), preventable complication rate (0.89% vs 1.28%; relative risk, 1.43; 95% confidence interval, 1.06-1.91; P = .02), and nonpreventable complication rate (4.75% vs 5.81%; relative risk, 1.22; 95% confidence interval, 1.08-1.39; P = .002).'] Do impact of the 80-hour workweek on patient care at a level I trauma center?