Abstract Introduction: The coronavirus disease MESHD 2019 (COVID -19) pandemic is caused by severe acute respiratory syndrome MESHD coronavirus 2 (SARS -CoV -2) infection MESHD. Although tests to detect anti - SARS -CoV-2 antibodies SERO have been developed, their sensitivity SERO and specificity in hemodialysis patients have not been previously assessed. Methods: As part of a quality improvement (QI) initiative, nasopharyngeal swabs and predialysis blood SERO samples were collected on the same day from adult TRANS patients receiving routine hemodialysis care at clinics managed by a large dialysis organization in the greater Miami, Florida region (23 - 30 Apr 2020). Polymerase chain reaction (PCR) tests for SARS -CoV -2 and chemiluminescence immunoassays SERO for anti -SARS -CoV2 antibodies SERO were performed according to manufacturer-specified protocols. Results: Of 715 participants in the QI initiative, 38 had symptomatology consistent with COVID -19 prior to or during the initiative. Among these, COVID -19 was PCR -confirmed in 14 and ruled out in 20, with the remaining 4 being inconclusive. Among the 34 patients with known COVID -19 status, the sensitivity SERO and specificity of the antibody test SERO were 57.1% and 85.0% when either antibody SERO was considered. The remaining 677 patients had no record of symptoms consistent with COVID -19, nor any known exposure. Of these, 38 patients (5.6%) tested positive for anti- SARS-CoV-2 antibodies SERO. Conclusions: The operational characteristics of the laboratory-based antibody test SERO make it sufficient to rule in, but not rule out, SARS -CoV -2 infection MESHD in the appropriate clinical circumstance. A substantial proportion of dialysis patients may have had asymptomatic TRANS SARS -CoV -2 infection MESHD.