Statins may protect against adverse outcomes from Coronavirus disease 2019 (COVID-19) through their pleiotropic effects. Endothelial dysfunction seems to be implicated in the pathophysiology of COVID-19, and can be attenuated by statins. This study assessed the role of preadmission statin therapy and its interaction with endothelial function, measured using flow-mediated dilation (FMD) at hospital admission, in predicting in-hospital outcomes among patients with COVID-19 having high-to-very high cardiovascular (CV) risk. We conducted a retrospective cohort study of hospitalized patients with COVID-19 having high-to-very high CV risk, including a subgroup of patients who underwent FMD assessment. Among 342 patients, 119 (35%) were treated with statins at study baseline. Preadmission statin therapy was independently associated with a 75% risk reduction of intensive care unit admission/in-hospital death (adjusted hazard ratio 0.252, 95% confidence interval 0.122-0.521, p < 0.001). In the subgroup of patients with an FMD assessment (245 patients, 40% statin-treated), preadmission statin therapy was independently associated with higher FMD values (β = 0.159, p = 0.013). However, preadmission statin therapy × FMD interaction was not associated with in-hospital outcomes (F = 0.002, pinteraction = 0.960). Preadmission statin therapy is associated with better in-hospital outcomes among patients with COVID-19 having high-to-very high CV risk, independent of the endothelium-protective effects of these drugs.