IMPORTANCE Pathology-based measures of human papillomavirus (HPV) status are routinely obtained in the care of head and neck cancer and are clearly associated with patient outcome for cancers of the oropharynx. However, it is unclear if HPV status is of high value for cancers of the larynx and oral cavity. In addition, it is possible to assess HPV infection using serology-based methods however, the suitability of this pathology-independent measure for predicting patient outcome in head and neck cancer is unknown. OBJECTIVE To investigate whether immunologic response to HPV16 is associated with patient survival across anatomic sites, independent of smoking and drinking history. DESIGN, SETTING, AND PARTICIPANTS Thiswas a population-based study of 1054 patients with head and neck cancer in the greater Boston, Massachusetts, area (1999-2003, 2006-2011). MAIN OUTCOMES AND MEASURES All-cause survival in relation to HPV16 E6 and E7 seropositivity. RESULTS The 1054 patients reflected the demographics of those treated in this timeframe (75%male mean age, 59 years). Seropositivity was very strongly associated with improved survival overall (hazard ratio HR], 0.33 95%CI, 0.24-0.45 P < .001), with no evidence that the magnitude of immune response, as assessed by titer levels, effected outcome. Seropositivity was associated with improved patient survival across all head and neck cancer sites: HR for oropharynx cancer, 0.26 95%CI, 0.18-0.39 for oral cavity cancer, 0.45 95%CI, 0.18-0.80 and for larynx cancer, 0.29 95%CI, 0.10-0.85. In addition, the associations with seropositivity were similar across smoking and/or drinking exposure groups: HR for low exposure, 0.52 95%CI, 0.20-1.36 for moderate exposure, 0.42 95%CI, 0.25-0.70 for heavy exposure, 0.51 95%CI, 0.36-0.73. In a subset of 162 patients with both HPV serology and p16 immunohistochemical (IHC) measures available, both measures were similarly associated with survival in the oropharynx (HR for serology, 0.16 95%CI, 0.03-0.47 for p16 measures, 0.16 95%CI, 0.03-0.46), whereas only serology was associated with outcome when considering all head and neck cancer cases (HR for serology, 0.49 95%CI, 0.23-1.04 for p16, 0.65 95%CI, 0.30-1.42). CONCLUSIONS AND RELEVANCE Collectively, these data suggest that a positive serologic response to HPV16 oncoproteins may be the best approach to assess HPV-disease for clinical outcome because it is associated with survival for all types of disease and is a marker that is not dependent on pathology material.