Introduction After the first wave of the COVID-19 pandemic, with the relief of the restrictive measures imposed on companies, it is pertinent to assess the immunity acquired to SARS-CoV-2 in the working population. Objectives To evaluate the prevalence of specific antibodies against SARS-CoV-2 and to analyze the presumed immunity to SARS-CoV-2 in a sample of workers from a company in the region of Aveiro. Methodology This is an observational study, in a population of 400 workers, estimating a sample of 197. The serological evaluation took place between 14/May and 28/June/2020. Workers were taken a capillary whole blood sample and performed the Tell Me Fast Rapid Diagnostic Test Coronavirus (COVID-19) IgG/ IgM Antibody Test (S/P/WB). Results During the defined period, a test was performed on 181 workers, it was found that 96.6% of the workers presented IgG/IgM Negative, 1.7% IgG/IgM Positive and 1.7% IgG Positive/IgM Negative, estimating the prevalence of SARS-CoV-2 infection in company workers at 3.4%. Conclusions There is a presumed low group immunity and a potential risk of SARS-CoV-2 infection in the working community. The Occupational Health Service must identify potential risks of SARS-CoV-2 infection in the workplace, design strategies and implement additional and preventive measures that contribute to reducing the SARS-CoV-2 incidence rate in workers and preventing a potential outbreak in the company, showing the importance of teaching and training workers to adhere to the COVID-19 contingency plan. Keywords: Personnel Management; Occupational Health; COVID-19; SARS-CoV-2; Antibodies; Serologic Tests.