Objective: The study aim was to quantify the burden of complications of pancreatoduodenectomy (PD). Background: The Postoperative Morbidity Index (PMI) is a quantitative measure of the average burden of complications of a procedure. It is based on highly validated systems-ACS-NSQIP and theModified Accordion Severity Grading System. Methods: Nine centers contributed ACS-NSQIP complication data for 1589 patients undergoing PD from 2005 to 2011. Each complication was assigned a severity weight ranging from 0.11 for the least severe complication to 1.00 for postoperative death, and PMIwas derived. Contribution to total burden by each complication grade was used to generate a severity profile ("spectrogram") for PD. Associations with PMI were determined by regression analysis. Results: ACS-NSQIP complications occurred in 528 cases (33.2%). The non- risk-adjusted PMI was 0.115 (SD = 0.023) for all centers and 0.113 (SD = 0.005) for the 7 centers that contributed at least 100 cases. Grade 2 complications were predominant in frequency, and the most common complication was postoperative bleeding/transfusion. Frequency and burden of complications differed markedly. For instance, severe complications (grades 4/5/6) accounted for only about 20% of complications but for more than 40% of the burden of complications. Organ space infection had the highest burden of any complication. The average burden in cases in which a complication actually occurred was 0.346. Conclusions: This study develops a quantitative non-risk-adjusted benchmark for postoperative morbidity of PD. The method quantifies the burden of types and grades of postoperative complications and should prove useful in identifying areas that require quality improvement.