OBJECTIVES: Anastomotic leaks after colorectal surgeries can lead to complications, and considerably increase medical resource use and cost. This study quantified the incidence, and clinical and economic burden of anastomotic leaks following colorectal surgeries in the US. METHODS: Premier Perspective database was used to identify patients having a set of colorectal surgeries between Jan 2008 to Dec 2010. The colorectal surgeries included colectomy, hemicolectomy, and rectum resection. The anastomotic leak event was defined by re-operation, re-anastomosis, stent, colostomy, drainage, and abscess within 30-day window following the index colorectal surgeries. The index surgery and re-intervention were identified by ICD-9 procedure codes, CPT codes and Standard Charge Master codes. This study entails two analyses: (1) the overall incidence rate of 30-day anastomotic leak; (2) the differences in LOS, readmission, post-operative infection, and total inpatient costs between the patients with anastomotic leaks and those without leaks. Chi square test and T test were used to compare outcomes between two cohorts, before and after employing propensity-score matching technique based on a series of baseline covariates. Generalized linear model was also conducted. RESULTS: A total of 6174 (6.18%) patients with colorectal surgeries had 30-day anastomotic leak during 2008-2010.The patients with anastomotic leak had 1.3 times higher 30-day readmission (p<0.01), and 1.9 times higher postoperative infection (p<0.01) compared to the patient without anastomotic leak. Anastomotic leak incurred additional LOS of 7.3 days and additional average hospital cost of $24,399 for index hospitalization alone. When the extra burden of readmission was added, the average incremental LOS increased to 9.5 days, and the average incremental hospital costs increased to $28,597. CONCLUSIONS: Anastomotic leaks in colorectal surgeries increase clinical and economic burden by 0.5 to 1.8 times in terms of additional readmission, postoperative infection, LOS, and hospital costs. The results underscore the potential advantage of cost reduction by preventing the anastomotic leaks after colorectal surgeries.