Introduction. There is negligible evidence on the efficacy of ivermectin for treating COVID-19 pneumonia. This study aimed to assess the efficacy of ivermectin for pre-emptively treatingStrongyloides stercoralishyperinfection syndrome in order to reduce mortality and the need for respiratory support in patients hospitalized for COVID-19. Methods. This single-center, observational, retrospective study included patients admitted with COVID-19 pneumonia at Hospital Vega Baja from 23 February 2020 to 14 March 2021. Because strongyloidiasis is endemic to our area, medical criteria support empiric administration of a single, 200 μg/kg dose of ivermectin to preventStrongyloideshyperinfection syndrome. The outcome was a composite of all-cause in-hospital mortality and the need for respiratory support. Results. Of 1167 patients in the cohort, 96 received ivermectin. After propensity score matching, we included 192 patients. The composite outcome of in-hospital mortality or need for respiratory support occurred in 41.7% of the control group (40/96) and 34.4% (33/96) of the ivermectin group. Ivermectin was not associated with the outcome of interest (adjusted odds ratio [aOR] 0.77, 95% confidence interval [CI] 0.35, 1.69;p= 0.52). The factors independently associated with this endpoint were oxygen saturation (aOR 0.78, 95% CI 0.68, 0.89,p< 0.001) and C-reactive protein at admission (aOR: 1.09, 95% CI 1.03, 1.16,p< 0.001). Conclusions. In hospitalized patients with COVID-19 pneumonia, ivermectin at a single dose for pre-emptively treatingStrongyloides stercoralisis not effective in reducing mortality or the need for respiratory support measures.