BACKGROUND:The pandemic of new severe acute respiratory syndrome (SARS) due to coronavirus (CoV) 2 (SARS-CoV-2) has stressed the importance of effective diagnostic and prognostic biomarkers of clinical worsening and mortality. Epidemiological data showing a differential impact of SARS-CoV-2 infection on women and men has suggested a potential role for testosterone (T) in determining gender-disparity in the SARS-CoV-2 clinical outcomes. OBJECTIVES:To estimate the association between T level and SARS-CoV-2 clinical outcomes (defined as conditions requiring transfer to higher or lower intensity of care or death) in a cohort of patients admitted in the Respiratory Intensive Care Unit (RICU) MATERIALS AND METHODS: A consecutive series of 31 male patients affected by SARS-CoV-2 pneumonia and recovered in the Respiratory Intensive Care Unit (RICU) of the "Carlo Poma" Hospital in Mantua were analyzed. Several biochemical risk factors (i.e., blood count and leucocyte formula, C- Reactive Protein (CRP), procalcitonin (PCT), Lactic Dehydrogenase (LDH), Ferritin, D-Dimer, Fibrinogen, Interleukin 6 (IL-6)) as well as total testosterone (TT), calculated free T (cFT), Sex Hormone Binding Globulin (SHBG), and Luteinizing Hormone (LH) were determined. RESULTS:Lower TT and cFT were found in the transferred to ICU/deceased in RICU group vs. groups of patients transferred to IM or maintained in the RICU in stable condition. Both TT and cFT showed a negative significant correlation with biochemical risk factors (i.e. the neutrophil count, LDH and PCT) but a positive association with the lymphocyte count. Likewise, TT was also negatively associated with CRP and ferritin levels. A steep increase of both ICU transfer or mortality risk was observed in men with TT<5 nmol/L or cFT< 100 pmol/L. DISCUSSION AND CONCLUSION:Our study demonstrates for the first time that lower baseline levels of TT and cFT levels predict poor prognosis and mortality in SARS-CoV-2 infected men admitted to RICU.