Introduction: There is no consensus on the optimal duration of post-treatment follow-up after head and neck cancer (HNC). To generate site-specific input for follow-up guidelines, this study describes the incidence and timing of manifestations of disease during five years of follow-up. Methods: All patients diagnosed with HNC in the Netherlands in 2015 were selected from the Netherlands Cancer Registry. The follow-up events local recurrence (LR), regional recurrence (RR), second primary tumour (SPT), distant metastasis (DM) and death were studied per follow-up-year. The cumulative incidence of these events was calculated using competing risk analyses, with LR, RR and SPT of the head and neck (SPHNC) as events and SPT outside the head-neck (SPOHN), DM and death as competing events. Analyses were performed for oral cavity-, oropharynx-, larynx- and hypopharynx squamous cell carcinoma (SCC), and all HNC patients. Results: The 1-, 1.5-, and 2-year cumulative incidence of an event (LR, RR, SPHNC) were 10% (95%CI 8–13), 12% (95%CI 10–15), and 13% (95%CI 10–16) for oral cavity SCC; 6% (95%CI 4–9), 10% (95%CI 7–14), and 11% (95%CI 8–15) for oropharynx SCC; 7% (95%CI 5–10), 11% (95%CI 9–15), and 13% (95%CI 10–16) for larynx SCC and 11% (95%CI 6–19), 19% (95%CI 12–27), and 19% (95%CI 12–27) for hypopharynx SCC. Conclusions: One year of follow-up for oral cavity SCC, and 1.5 years for oropharynx-, larynx-, and hypopharynx SCC suffices for the goal of detecting disease manifestations after treatment. More research into other aspects of follow-up care should be performed to determine the optimal follow-up regimen.