ImportancePatients with head and neck cancer (HNC) have an increased risk of malnutrition, partly due to disease location and treatment sequelae. Although malnutrition is associated with adverse outcomes, there is little data on the extent of outcomes and the sociodemographic factors associated with malnutrition in patients with HNC.ObjectivesTo investigate the association of race, ethnicity, and payer type with perioperative malnutrition in patients undergoing HNC surgery and how malnutrition affects clinical outcomes.Design, Setting, and ParticipantsThis retrospective cohort study used data from the Premier Healthcare Database to assess adult patients who had undergone HNC surgery from January 2008 to June 2020 at 482 hospitals across the US. Diagnosis and procedure codes were used to identify a subset of patients with perioperative malnutrition. Patient characteristics, payer types, and hospital outcomes were then compared to find associations among race, ethnicity, payer type, malnutrition, and clinical outcomes using multivariable logistic regression models. Analyses were performed from August 2022 to January 2023.Exposure(s)Race, ethnicity, and payer type for primary outcome, and perioperative malnutrition status, race, ethnicity, and payer type for secondary outcomes.Main Outcome(s) and Measure(s)Perioperative malnutrition status. Secondary outcomes were discharge to home after surgery, hospital length of stay (LOS), total cost, and postoperative pulmonary complications (PPCs).ResultsThe study population comprised 13 895 adult patients who had undergone HNC surgery during the study period; they had a mean (SD) age of 63.4 (12.1) years; 9425 male (67.8%) patients; 968 Black (7.0%), 10 698 White (77.0%), and 2229 (16.0%) individuals of other races; and 887 Hispanic (6.4%) and 13 008 non-Hispanic (93.6%) individuals. Among the total sample, there were 3136 patients (22.6%) diagnosed with perioperative malnutrition. Compared with White patients and patients with private health insurance, the odds of malnutrition were higher for non-Hispanic Black patients (adjusted odds ratio [aOR], 1.31; 95% CI, 1.11-1.56), Medicaid-insured patients (aOR, 1.68; 95% CI, 1.46-1.95), and Medicare-insured patients (aOR, 1.24; 95% CI, 1.10-1.73). Black patients and patients insured by Medicaid had increased LOS, costs, and PPCs, and lower rates of discharge to home. Malnutrition was independently associated with increased LOS (β, 5.20 additional days; 95% CI, 4.83-5.64), higher costs (β, $15 722 more cost; 95% CI, $14 301-$17 143), increased odds of PPCs (aOR, 2.04; 95% CI, 1.83-2.23), and lower odds of discharge to home (aOR, 0.34; 95% CI, 0.31-0.38). No independent association between malnutrition and mortality was observed.Conclusions and RelevanceThis retrospective cohort study found that 1 in 5 patients undergoing HNC surgery were malnourished. Malnourishment disproportionately affected Black patients and patients with Medicaid, and contributed to longer hospital stays, higher costs, and more postoperative complications.