OBJECTIVE To determine the prevalence of varying classes of obesity in patients undergoing tracheostomy and the associated complication rates as compared with nonobese patients. METHODS A retrospective chart review was performed from 2012 to 2018 on all patients who underwent open tracheostomy by the Department of Otolaryngology-Head and Neck Surgery. METHODS All tracheostomies were performed at a single tertiary care center. METHODS Patients were classified by body mass index (BMI) according to the World Health Organization classification system: underweight (<18.5), normal-overweight (18.5-29.9), class I (30-34.9), class II (35-39.9), and class III (>40). Charts were reviewed for patient demographic information, Charlson Comorbidity Index score, surgical indication, operative time, tracheostomy tube type, and postoperative complications. RESULTS A total of 387 patients (mean ± SD BMI, 31.3 ± 14.2) were identified per the inclusion/exclusion criteria. Of patients with BMI >30 (n=153), 34.6% were categorized as obesity class I, 29.4% as class II, and 35.9% as class III. The most common indication for tracheostomy was malignancy in nonobese patients (41.5%) and respiratory failure for obese patients (58.2%). Operative time was significantly longer in obese patients, and most of these patients required an extended-length tracheostomy tube. Patients with a BMI >40 had higher rates of multiple postoperative complications or death (P = .009). Underweight patients also had a higher rate of complication than normal-overweight patients (P = .016). CONCLUSIONS Class III and underweight patients had higher rates of postoperative complications, which should be taken into consideration during perioperative counseling.