Background The problem of obesity has risen to epidemic levels in the United States. A subset of patients with obesity will have metabolic syndrome. We sought to examine the impact of metabolic syndrome on the risk of morbidity and mortality among a large cohort of patients who underwent hepatic resection. Methods Patients included in the National Surgical Quality Improvement Program (NSQIP) dataset who underwent hepatic resection between January 2005 and December 2008 were identified. Data on clinical characteristics, comorbidities, operative details, as well as postoperative complications and mortality were collected and analyzed. Patients with BMI >30 kg/m2 who also had hypertension and diabetes were defined as having metabolic syndrome. Results A total of 3,973 patients who underwent a liver resection were identified. Overall mean body mass index was 28 kg/m2; 31.7% patients were obese (>30 kg/m2). Of the patients who were obese, 256 (20%) had metabolic syndrome. Patients with metabolic syndrome were less likely to have had a major hepatectomy (≥hemi-hepatectomy, 36% vs 43%; P = .01) but had a greater mean number of red blood cell transfusions (1.6 vs 1; P = .02). The incidence of postoperative complications after hepatectomy was 23%. Patients with metabolic syndrome had a greater risk for reintubation (odds ratio [OR] 1.9; P = .02), >48 hours ventilator dependence (OR 2.0; P = .003), myocardial infarction (OR 5.5; P = .01) and superficial surgical-site infections (OR 1.7; P = .02) compared with nonmetabolic patients. Overall postoperative mortality was 3%. Metabolic syndrome was associated with an increased risk of postoperative death (OR 2.7; P = .001). Conclusion The presence of metabolic syndrome was associated with a greater risk of perioperative complications. In addition, patients with metabolic syndrome had greater than a 2-fold increased risk of death after hepatic resection.