Obesity has been associated with increased risk for postoperative CSF leak in patients with benign cranial nerve tumors. Other measures of postoperative morbidity associated with obesity have not been well characterized.Patients enrolled in the American College of Surgeons' National Surgical Quality Improvement Program (ACS-NSQIP) from 2007 to 2013 with a diagnosis code of a benign neoplasm of a cranial nerve were included. The primary outcome of postoperative morbidity was analyzed as well as secondary outcomes of readmission and reoperation. The main covariate of interest was body mass index (BMI).A total of 561 patients underwent surgery for a benign cranial nerve neoplasm between 2007 and 2013. Readmission data, available for 2012-2013(n=353), revealed hydrocephalus, facial nerve injury, or CSF leak requiring readmission or reoperation occurred in 0.85%, 1.42%, and 3.12%, respectively. Composite morbidity included wound complications, infection, respiratory insufficiency, transfusion requirement, stroke, venous thromboembolism, coma and cardiac arrest. On multivariable analysis patients with class I (BMI 30-34.9) and II (BMI 35-39.9) obesity showed trends towards increasing return to operating room, though not significant, but there was no trend for composite complications in class I and II obesity patients. However, class III obesity, BMI≥40, was associated with increased odds of composite morbidity (OR 4.40, 95% CI 1.24-15.88) and return to the operating room (OR 5.97, 95% CI 1.20-29.6) relative to patients with a normal BMI, 18.5-25.Obesity is an independent and important risk factor for composite morbidity in resection of benign cranial nerve neoplasms, and as such, merits discussion during preoperative counseling.