One factor that affects surgical team performance is unprofessional behavior exhibited by the surgeon, which may be observed by patients and families and reported to health care organizations in the form of spontaneous complaints. The objective of this study was to assess the relationship between patient complaints and adverse surgical outcomes. A retrospective cohort study used American College of Surgeons National Surgical Quality Improvement Program data from an academic medical center and included 10 536 patients with surgical procedures performed by 66 general and vascular surgeons. The number of complaints for a surgeon was correlated with surgical occurrences (P < .01). Surgeons with more patient complaints had a greater rate of surgical occurrences if the surgeon's aggregate preoperative risk was higher (β = .25, P < .05), whereas there was no statistically significant relationship between patient complaints and surgical occurrences for surgeons with lower aggregate perioperative risk (β = −.20, P = .77).