In our institution a total of 145 patients were hospitalized with an in-house laboratory confirmed COVID-19 diagnosis. In this group, the presence of SARS-CoV-2 was confirmed using RT-PCR on the first nasopharyngeal and/or throat swab in 132 patients (91%). Another 4 patients were diagnosed with a second nasopharyngeal and 1 patient with an anal swab. Next, 5 patients were found to be positive on BAL samples. Three patients remained negative on repetitive swabs. These patients were not eligible for a BAL sampling procedure or did not present with respiratory symptoms and as such serological testing was performed. All 3 patients were found to be positive for IgG SARS-CoV-2 serology (Prima Professional®). Given the high pre-test probability for SARS-Cov-2 in this prospective cohort and repetitive testing, the added diagnostic value of SARS-CoV-2 serology in providing a diagnosis in this cohort was 2%.