During the SARS-CoV-2 pandemic, many workplaces were forced to interrupt their activities or alternatively had to prefer a smart way of working, if this was compatible with their activities, to contain the spread of the virus. Some production activities, on the other hand, continued, such as those belonging to the agri-food sector. The aim of the study was to investigate seroprevalence in the workers of an Italian agri-food company following prevention interventions developed in concert with an occupational physician. An observational cohort study was conducted on a population of 328 (100%) workers of a company in the agri-food sector, located in the Sicilian region, which specialized in the production and distribution of citrus fruits. Only one worker was infected with SARS-CoV-2, which later also developed the immune response. No other worker contracted the infection. In conclusion, the measures implemented identified the positive subject for SARS-CoV-2 at an early stage. This made it possible to avoid contagion between the positive subject and the other workers. The occupational physician was also, in this case, essential in decoding and implementing the rules and guidelines useful for the protection of the health and safety of the worker.