AbstractHypercoagulability and thrombosis caused by coronavirus disease 2019 (COVID‐19) are related to the higher mortality rate. Because of limited data on the antiplatelet effect, we aimed to evaluate the impact of aspirin add‐on therapy on the outcome of the patients hospitalized due to severe COVID‐19. In this cohort study, patients with a confirmed diagnosis of severe COVID‐19 admitted to Imam Hossein Medical Center, Tehran, Iran from March 2019 to July 2020 were included. Demographics and related clinical data during their hospitalization were recorded. The mortality rate of the patients was considered as the primary outcome and its association with aspirin use was assessed. Nine hundred and ninety‐one patients were included, of that 336 patients (34%) received aspirin during their hospitalization and 655 ones (66%) did not. Comorbidities were more prevalent in the patients who were receiving aspirin. Results from the multivariate COX proportional model demonstrated a significant independent association between aspirin use and reduction in the risk of in‐hospital mortality (0.746 [0.560–0.994], p = 0.046). Aspirin use in hospitalized patients with COVID‐19 is associated with a significant decrease in mortality rate. Further prospective randomized controlled trials are needed to assess the efficacy and adverse effects of aspirin administration in this population.