Objectives: We aim to evaluate the impact of MetS on the short-term postoperative outcomes of complex head and neck surgery patients. Methods: This is a retrospective cohort analysis of the 2005 to 2017 National Surgical Quality Improvement Program (NSQIP) database. NSQIP database was queried for 30-day outcomes of patients undergoing complex head and neck surgeries, defined as laryngectomy or mucosal resection followed by free tissue transfer, similar to prior NSQIP studies. Patients with hypertension, diabetes, and body mass index (BMI) >30 kg/m2 were defined as having MetS. Adverse events were defined as experiencing readmission, reoperation, surgical/medical complications, or mortality. Results: A total of 2764 patients (27.0% female) with a mean age of 62.0 ± 11.7 years were included. Patients with MetS (n = 108, 3.9%) were more likely to be female ( P = .017) and have high ASA classification ( P = .030). On univariate analysis, patients with MetS were more likely to require reoperation (25.9% vs 16.7%, P = .013) and experience medical complications (26.9% vs 15.4% P = .001) or any adverse events (61.1% vs 48.7%, P = .011) compared to patients without MetS. On multivariate logistic regression after adjusting for age, sex, race, ASA classification, and complex head and neck surgery type, MetS was an independent predictor of medical complications (odds ratio 2.34, 95% CI 1.28-4.27, P = .006). Conclusion: Patients with MetS undergoing complex head and neck surgery are at increased risk of experiencing medical complications. Identifying patients with MetS can therefore aid surgeons in preoperative risk assessment and help improve postoperative management. Level of Evidence: N/A