OBJECTIVES:  To estimate economic burden of three major complications: anastomotic leak (AL), bleeding and infection, in patients undergoing lower anterior resection (LAR) surgery. METHODS: The Premier Perspective® Database containing billing data from over 600 hospitals in the U.S was used. Included patients were >18 years of age and had an elective LAR from 2008 to 2014. AL, bleeding and infection, were identified using ICD-9 diagnosis codes. Generalized Estimating Equations (GEE) models were used to estimate impact of each complication on length of stay (LOS), operating room time (ORT) and hospital costs (HC) after controlling for patient, procedure, and hospital factors. GEE accounted for the clustering of patients within hospitals; separate models were run for each complication. RESULTS: A total of 13,789 patients underwent LAR with an average age of 62.1 (range: 18-89) years. Incidence of AL, bleeding and infection was 12.7%, 9.1% and 5.6% respectively. On average, the LOS, ORT and HC of the LAR patients were 6.4 (SD: 4.8) days, 235.2 (SD: 215.9) minutes, and $19,030 (SD: $15,846). In the GEE models, LOS was 80.8% (95% CI: 74.2%-87.6%), OPT 9.7% (6.7%-12.8%), and HC 58.5% (51.9%-65.4%) higher in patients who had AL than those who did not have AL. Similarly, LOS, OPT and HC were 35.3% (29.3%-41.6%), 10.7% (7.7%-13.8%), and 36.7% (29.7%-44.0%) higher in patients with bleeding. Consistent results were observed for infection with 115.3% (102.6%-128.8%), 11.0% (6.1%-16.2%), and 106.0% (91.5%-121.7%) higher LOS, OPT and HC in patients with infection compared to those who did not incur an infection. The differences of all measures between patients with a complication and those without it were statistically significant (p<0.0001). CONCLUSIONS:  This study demonstrates that complications such as AL, bleeding and infection occur frequently in LAR and are associated with significant economic burden.