Abstract: Obstructive sleep apnea (OSA) prevalence is estimated to be 3-7% in the general population, with the vast majority of those with the disorder undiagnosed. In patients who have been treated for head and neck cancer, the prevalence of OSA is even higher, with estimates ranging from 12% to 96%. Thus, we suspected that this patient population would suffer from avery high prevalence of untreated OSA. To investigate this, we performed a retrospective chart review of 282 patients who underwent surgery for head or neck malignancy, noting whether OSA screening, diagnosis, treatment, or symptoms were present. We found that 15 patients werealready diagnosed with OSA before surgery, but only 1 patient was screened, diagnosed, and treated for OSA after surgery, resulting in a total of 16 patients with OSA (5.67%). This percentage was significantly lower than even the lowest estimated prevalence for those with head and neck cancer, indicating that a sizable number of patients were likely undiagnosed and untreated. A contributing factor in this may have been that 38 patients had OSA symptoms, but 36 of these patients were not screened at all, with only one patient screened and another patient diagnosed before surgery. We recommend researching why those with OSA symptoms are so often not screened, as well as developing interventions that encourage healthcare providers to screen for OSA more often, especially when caring for patients with head and neck cancer whoare highly susceptible for OSA.