Background: Extensive data exist on the morbidity and mortality of patients undergoing pancreaticoduodenectomy (PD), but there are few reports about hospital readmissions following this procedure. Objective: This study was designed to evaluate the number of/reasons for readmission after initial discharge following PD and the factors influencing readmission, including the influence of initial length of stay (LOS). Methods: We reviewed the initial hospitalization and subsequent readmissions for 1643 patients undergoing PD between 01/1996 and 12/2003. Patients readmitted for reasons unrelated to their PD or underlying disease process were excluded. Patients were grouped by readmission status and compared using chi-square and Wilcoxon rank sum-tests. Logistical regression was used to determine the odds ratios of the variables found to increase the likelihood of hospital readmission following PD. Results: 431 of 1643 patients (26%) were readmitted to our institution a total of 678 times after PD. Patients readmitted were younger (mean=61.8 vs 64.6 yrs, p<0.0001), but had no significant differences in gender, comorbidities, presenting symptoms, or final pathology. 72% of patients were readmitted within 1 yr following PD, while 28% were readmitted after 1 yr. Within the first year, patients were more likely to be readmitted for postop complications such as delayed gastric emptying (DGE, 12% vs. 4%, p=0.01), intraabdominal abscess (17% vs. 4%p<0.0001), and wound infections (6% vs. 1%, p=0.02). Patients readmitted after a year were more likely to have incisional hernias (12% vs. 3%, p<0.0001), obstructive jaundice (17% vs. 4%, p<0.0001), and/or metastatic disease (12% vs. 5%, p<0.0001). Factors from the initial hospitalization most strongly associated with readmission were vessel resection at surgery (OR=3.2, 95%CI=1.25-8.23), intraabdominal abscess (OR=2.7, 95%CI=1.6-4.8), wound infection (OR=1.8, 95%CI=1.1-2.8), and DGE (OR=1.5, 95%CI=1.03-2.22). The LOS did decrease over time, with a median LOS of 10.5 days in 1996 vs 7 days in 2003. The percentage of patients being readmitted after PD decreased as well with 33.1% being readmitted in 1996 compared to 20.1% (p=0.004) in 2003. Conclusions: Readmission following PD is a common occurrence, observed in 26% of patients. For patients readmitted in the first year, the readmission is more commonly related to postop complications while those readmitted after a year more often have metastatic disease or recurrent jaundice. Postop complications and vessel resection are independent risk factors for readmission. Finally, early hospital readmission rate has not increased in association with a decreased LOS after PD.