Objective:To determine whether trauma patients managed by an admitting or consulting service with a high proportion of physicians exhibiting patterns of unprofessional behaviors are at greater risk of complications or death.Summary Background Data:Trauma care requires high-functioning interdisciplinary teams where professionalism, particularly modeling respect and communicating effectively, is essential.Methods:This retrospective cohort study used data from 9 level I trauma centers that participated in a national trauma registry linked with data from a national database of unsolicited patient complaints. The cohort included trauma patients admitted January 1, 2012 through December 31, 2017. The exposure of interest was care by 1 or more high-risk services, defined as teams with a greater proportion of physicians with high numbers of patient complaints. The study outcome was death or complications within 30 days.Results:Among the 71,046 patients in the cohort, 9553 (13.4%) experienced the primary outcome of complications or death, including 1875 of 16,107 patients (11.6%) with 0 high-risk services, 3788 of 28,085 patients (13.5%) with 1 high-risk service, and 3890 of 26,854 patients (14.5%) with 2+ highrisk services (P < 0.001). In logistic regression models adjusting for relevant patient, injury, and site characteristics, patients who received care from 1 or more high-risk services were at 24.1% (95% confidence interval 17.2% to 31.3%; P < 0.001) greater risk of experiencing the primary study outcome.Conclusions:Trauma patients who received care from at least 1 service with a high proportion of physicians modeling unprofessional behavior were at an increased risk of death or complications.