Introduction The continuing hospitalization of patients with postoperative traumatic defects of the pancreatobiliary ductal system, despite the improvements in surgical aids and skills in the past decade, has stimulated a rereview of this problem from a technical standpoint. In analysis of such cases in the literature 2 etiological factors are uniformly reiterated: (1) inadequate personal surgical skill and (2) unrecognized deviations from the anatomical "normal." The authors defer correction of the former to the category of improvements in modern surgical education. However, it is believed that dissolution of the latter as an etiological agent of a critical postoperative complication can be effected by more thorough knowledge of the surgical anatomy of the region involved. To this end a detailed anatomical dissection of the complete pancreatobiliary ductal system was performed in 100 unselected autopsy specimens. The marked variation of anatomical relationships observed during this study has suggested that the term "normal