BackgroundHeadache is one of the most frequently reported symptoms in post-COVID patients. The clinical phenotype of COVID-19 headache combines phenotypic features of both tension-type headache (TTH) and migraine. We aimed to assess the effectiveness, side effects and predictors of amitriptyline (AMT) response in a real-world study setting.MethodsWe performed an observational multicentric study with a retrospective cohort. All consecutive patients with confirmed COVID-19 infection who received AMT for post-COVID headache from March 2020 to May 2021 were included. Response was evaluated by the reduction in the number of headache days per month (HDM) between weeks 8 and 12, compared with the baseline. We explored which variables were associated with a higher probability of response to AMT.ResultsForty-eight patients were eligible for the study, 40/48 (83.3%) females, aged 46.85 (SD: 13.59) years. Patients had history of migraine 15/48 (31.3%) or TTH 5/48 (10.4%). The mean reduction of HDM was 9.6 (SD: 10.9; 95% CI 6.5, 12.7) days. Only 2/48 (5%) of patients discontinued AMT due to poor tolerability. History of TTH (10.9, 95% CI 1.3, 20.6) and nausea (− 8.5, 95% CI − 14.6, − 2.5) were associated with AMT response.ConclusionsThis study provides real-world evidence of the potential benefit of AMT in patients with post-COVID-19 headache, especially in patients with history of TTH and without concomitant nausea.