Background: The coronavirus disease 2019 (COVID-19) pandemic began in Brazil on 26 February 2020. By 6 May 2023, 37.4 million cases had been confirmed, causing 701 thousand deaths in the country. We aimed to describe the epidemiological profile and clinical development of COVID-19 cases among the employees of a health institution, from acute infection to long COVID. Methods: This was a longitudinal study using a retrospective and prospective approach via questionnaires referring to epidemiological investigation, which was the inclusion criteria, and about long-term symptoms. Results: A total of 809 employees were detected with SARS-CoV-2 infection via RT-PCR, 466 of them answered the epidemiological investigation, and 101 completed the Long COVID Symptom Questionnaire. The most commonly affected employees were women (88.6%) working in patient care (68.6%). Headache, myalgia, cough, odynophagia, and runny nose were the most frequent symptoms. Only three employees (0.6%) required hospitalization, while the other employees required outpatient management due to mild symptoms. We identified 19 (4.1%) cases of reinfection, and 42 (41.6%) employees reported long-term symptoms, such as myalgia, dyspnea, and headache. Conclusions: Although most cases were mild with good outcomes, long COVID cases identified are noteworthy, as these symptoms may impact quality of life even months after SARS-CoV-2 infection.