OBJECTIVES: Anastomotic Leakage (AL) is a serious complication that may follow colorectal resection, increasing overall costs. The aim of this study was to assess the additional inpatient economic burden of AL at one Italian hospital. METHODS: 317 patients who underwent colorectal resection between January 2015 and December 2016 in Policlinico Universitario Campus Biomedico were included in this retrospective cohort study. For each patient, baseline demographics, clinical characteristics, healthcare resource utilization and costs were extracted from the hospital's database. The primary endpoint was inpatient costs. Bivariate comparisons were conducted between patients with and without AL using Chi square tests for categorical outcomes and t-tests or Wilcoxon rank sum test for continuous outcomes. RESULTS: Mean (SD) age in the cohort was 66.7 (13.2) years and 51.8% of patients were male. 79.5% of patients had malignant disease and 58.9% had an American Society of Anesthesiologists (ASA) score of 2/6. More patients had laparoscopic surgery (72.6%) compared to open, in 23% of cases derivative stoma was made during the primary operation. 39 patients (12.3%) developed AL during hospital stay. When compared to patients without AL, more AL patients were male (71.8% vs 51.8%), more had cancer (92.3% vs 77.7%) and more had a derivative stoma (20.5% vs. 9.9%). Age, surgery approach, are similar in two groups. In the bivariate analysis, patients with AL had significantly higher total inpatient costs (V14,781.8 vs V7,110.8, p<0.001), higher LOS (20.1 vs 10.3 days, p<0.001) and ICU admissions (38.5% vs 9.0%, p<0.001) relative to patients without AL. CONCLUSIONS: AL increases the inpatient costs 2 times in this Italian hospital. Reducing AL may improve quality of care and substantially reduce hospital costs while increasing the efficiency of resource utilization.