BACKGROUND: In head and neck cancer (HNC), 3‐month post‐treatment positron emission tomography (PET)/computed tomography (CT) reliably identifies persistent/recurrent disease. However, further PET/CT surveillance has unclear benefit. The impact of post‐treatment PET/CT surveillance on outcomes is assessed at 12 and 24 months. METHODS: A 10‐year retrospective analysis of HNC patients was carried out with long‐term serial imaging. Imaging at 3 months included either PET/CT or magnetic resonance imaging, with all subsequent imaging comprised of PET/CT. PET/CT scans at 12 and 24 months were evaluated only if preceding interval scans were negative. Of 1114 identified patients, 284 had 3‐month scans, 175 had 3‐ and 12‐month scans, and 77 had 3‐, 12‐, and 24‐month scans. RESULTS: PET/CT detection rates in clinically occult patients were 9% (15 of 175) at 12 months, and 4% (3 of 77) at 24 months. No difference in outcomes was identified between PET/CT‐detected and clinically detected recurrences, with similar 3‐year disease‐free survival (41% vs 46%, P = .91) and 3‐year overall survival (60% vs 54%, P = .70) rates. Compared with 3‐month PET/CT, 12‐month PET/CT demonstrated fewer equivocal reads (26% vs 10%, P < .001). Of scans deemed equivocal, 6% (5 of 89) were ultimately found to be positive. CONCLUSIONS: HNC patients with negative 3‐month imaging appear to derive limited benefit from subsequent PET/CT surveillance. No survival differences were observed between PET/CT‐detected and clinically detected recurrences, although larger prospective studies are needed for further investigation. Cancer 2013. © 2012 American Cancer Society. Surveillance 12‐ and 24‐month post‐treatment positron emission tomography/computed tomography (PET/CT) scans are of limited yield in head and neck cancer patients with negative 3‐month imaging. No survival differences are observed between PET/CT‐detected and clinically detected recurrences.