Background: Antecedent use of renin angiotensin aldosterone inhibitors (RAASi) appears crucial to prevent clinical deterioration and protect against cardiovascular and/or thrombotic complications of Coronavirus Disease (COVID-19), for indicated patients. Doubts have been raised about continuing treatment throughout infection, and nothing is known regarding its effect with concomitant medications. Hence, the purpose of this paper is to evaluate the differential effect of RAASi continuation in patients hospitalized with COVID-19 according to diuretic use.Methods: We used the Coracle (epidemiology, clinical characteristics, and therapy in real life patients affected by Sars-Cov-2) multi-center registry, which contains data of hospitalized patients with COVID-19 from 4 regions of Italy. We performed analyses on adult (50+ years) records with admission on/after February 22, 2020 with a known mortality or discharge status as of April 1, 2020. We constructed a multivariable Firth logistic regression model to complete our objective.Results: There were 286 patients in this analysis. Overall, 100 (35.0%) patients continued RAASi and 186 (65%) discontinued. There were 98 patients who were treated with a diuretic; 51 (52%) of those continued RAASi. The in-hospital mortality rates among patients treated with a diuretic and continued vs. discontinued RAASi were 7.8% vs 25.5% (p = 0.0179). There were 188 patients who were not treated with a diuretic; 49 (26.1%) of those continued RAASi. The in-hospital mortality rates among patients who were not treated with a diuretic and continued vs. discontinued RAASi were 16.3% vs 9.4% (p = 0.1827). After accounting for age, congestive heart failure, and coronary heart disease/ischemic heart disease, continuing RAASi decreased the risk of mortality by approximately 72% (OR = 0.28, 95% CI = 0.08 – 0.94, p = 0.0391) for patients treated with diuretics, but did not alter the risk in patients who were not treated with diuretics.Conclusion: Diuretic use in hospitalized patients with COVID-19 who were on RAASi prior to admission was associated with increased risk of in-hospital mortality. Whether this combined therapy increases risk or is the reflection of a more severe presentation deserves further investigation. Continuing RAASi therapy in patients concomitantly treated with diuretics was associated with reduced in-hospital mortality.