BACKGROUND Total shoulder arthroplasty has been demonstrated to be an effective treatment for arthritis of the glenohumeral joint. Prior studies have identified longer operative times as a risk factor for complications after numerous types of procedures. We hypothesized that increased operative time, in 20-min intervals, would be associated with complications following total shoulder arthroplasty. METHODS Patients undergoing total shoulder arthroplasty from 2006 to 2015 were identified from the ACS-NSQIP database. Patient demographic information, perioperative parameters, and 30-day outcomes were retrieved. Pearson's Chi-square test and multivariate Poisson regression with robust error variance were used to analyze the relationship of operative time and outcomes. RESULTS A total of 10,082 patients were included. Multivariate analysis revealed that for each increase in 20 min of operative time, there were significantly increased rates of any complication (relative risk (RR) 1.24, 95% confidence interval (CI) 1.19-1.26), anemia requiring transfusion (RR 1.33, 95%CI 1.26-1.4), peripheral nerve injury (RR 1.88, 95%CI 1.53-2.31), and urinary tract infection (RR 1.24, 95%CI 1.09-1.41). CONCLUSIONS This study indicates that increasing operative time confers increased risk for postoperative complications following total shoulder arthroplasty. We anticipate the results of this manuscript will be used for provider education, policy decision-making, and potentially to derive algorithms that can improve safety and efficiency in total shoulder arthroplasty. METHODS III.