['Although a common clinical pairing, the epidemiology and prognosis of lung cancer (LC) after head and neck cancer (HNC) is not well described.', 'Data from the database of the Surveillance, Epidemiology and End Results (SEER) Program were used to study the epidemiology and survival of patients with LC after HNC. These data were compared with those from our institutional cancer registry.', 'Of all patients with a history of HNC in the SEER database, 8,225 (5%) patients went on to develop LC. This was more than three times the incidence of second primary lung cancers (1.5%). Subsequent LCs in patients with a history of HNC were more common among those with hypopharyngeal and laryngeal cancer and those with localized HNC. Patients with HNC followed by LC had poorer overall survival than did the overall population of patients with LCs in the SEER database. Overall survival after the onset of LC was dismal (median survival, 8 months). Survival was not affected by histologic concordance between HNC and LC. An analysis of 72 patients with LC after HNC reported in our institutional tumor registry over the past 37 years yielded similar results.'] Do previous head and neck cancers portend poor prognoses in lung cancer patients?