Objective:To determine the prevalence of hypotestosteronemia in chronically critically ill (CCI) men.Design:Prevalence survey.Setting:Step-down respiratory care unit (RCU) at a tertiary care teaching hospital.Patients:Thirty ventilator-dependent CCI men transferred from intensive care units (ICUs) within the same institution.Interventions:None.Measurements and Main Results:Total testosterone and bioavailable testosterone (bioT) concentrations were measured within 48 hrs of RCU admission. Patients were hospitalized a median of 40 days (range, 9-185 days) before RCU admission, with a median ICU length of stay of 25 days (range, 9-177 days). At RCU admission, total testosterone concentrations averaged 104 ± 96 ng/dL, with average bioT concentrations of 19 ± 20 ng/dL (16 ± 9% of total testosterone). Twenty-nine of the 30 patients (96%) had bioT concentrations well below the lower limit of normal for their age range. bioT concentrations, expressed as a percentage of the normal mean for each patient's age range, were positively correlated with the number of days that the patient was in the ICU before transfer to the RCU (n = 30, r2= .17,p= .025). However, if the single patient who remained in the ICU for 177 days was excluded, this correlation disappeared (n = 29, r2= .07,p= .09). No other relationship was found between bioT concentrations and any other variable, including type of patient, ICU length of stay, reason for either initial admission to the ICU or prolonged mechanical ventilation, type of nutritional support, or use of dopamine.Conclusions:CCI men have a very high prevalence of hypotestosteronemia, which may impede their recuperation and rehabilitation. Further studies are needed to determine whether additional pharmacologic treatment with testosterone can improve the recovery of these patients.