Background: The goal of surveillance is to detect potentially salvageable recurrence, allowing early salvage treatment and thereby improving clinical outcomes. Currently, there is limited data on the optimal frequency of imaging for head and neck cancer patients treated with definitive radiotherapy. This study aims to evaluate the cost-effectiveness of surveillance imaging in this group of patients. Methods: Eligible patients included those with a demonstrable disease free interval (≥ 1 follow up scan without evidence of disease and a subsequent visit/scan) treated between 2000-2010. Age, tumor site and stage, induction chemotherapy use, dose/ fractionation, mode of detection of recurrence, salvage therapy, number and modality of scans were recorded. Deaths from disease recurrence or from other causes were also recorded. Imaging costs were calculated based on the 2016 Medicare fee schedule. Results: 1508 patients were included. Mean age was 55.8 years (range: 17-87). Median overall survival was 99 months (range: 6-199). Mean imaging follow up period was 70 months. 190 (12.6%) patients had disease recurrence – 107 locoregional (LR) and 83 distant. 119 (62.6%) of the relapsed group were symptomatic and/or had an adverse clinical finding associated with recurrence. 80.4% of LR relapses presented with a clinical finding, while 60.2% of distant relapses were detected via imaging alone in asymptomatic patients. There was no difference between the successful salvage rates and overall survival between those with relapses detected clinically or via imaging alone. 70% of relapses occurred within the first 2 years post-treatment. In those who relapsed after 2 years, the median time to relapse was 51 months (2 LR and 11 distant relapses). After 2 years, the average cost for detecting a salvageable recurrence for image-detected group was $741 447.41, and the cost for preventing 1 recurrence-related death for image-detected disease was $889 736.89. The number of scans required to detect a salvageable recurrence in an asymptomatic patient after 2 years was 3512. Conclusions: Surveillance imaging in asymptomatic patients without clinically suspicious findings beyond 2 years requires judicious consideration.