© 2022 Ankara Microbiology Society. All rights reserved.The coronavirus disease-2019 (COVID-19) pandemic, which affects millions of people around the world, has been affecting our country since March 2020. The fact that the symptoms such as fever, myalgia, headache, joint pain which are common in COVID-19 patients are quite similar to the symptoms of diseases such as Crimean-Congo hemorrhagic fever (CCHF) and Brucellosis. This may cause a diagnostic confusion in regions where these diseases are seen as endemic. In this report, a patient hospitalized with a pre-diagnosis of COVID-19 and diagnosed with acute Brucellosis, CCHF and COVID-19 during followup was presented. A 31-year-old female patient living in a rural area admitted to the emergency service with complaints of fever, weakness, headache, and body/joint pain. Physical examination revealed a temperature of 38.3°C, a pulse rate of 102/minute, and a peripheral capillary oxygen saturation of 97% in room air. The system examination was normal. In the laboratory findings, an increase in liver enzymes and acute phase reactants was observed and the platelet count was at the lower limit of the normal range. In terms of COVID-19, no involvement compatible with COVID-19 was detected in the thorax computed tomography (CT) of the patient whose nasopharyngeal and oropharyngeal mixed swab samples were taken.The patient was transferred to our infectious diseases service with a pre-diagnosis of COVID-19 and CCHF. Serum samples were sent to the Public Health Agency Microbiology Reference Laboratory Department (PHA-MRLD) for CCHF diagnostic tests and supportive treatment was started. Brucella Rose Bengal and Coombs’ immuncapture (1/1280 titer) tests were found as positive in the patient, who was examined for brucellosis because of living in a rural area and having a history of consuming fresh dairy products. In the tests performed at PHA-MRLD, CCHF-specific IgM positivity and the presence of viral RNA were detected. Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) reverse-transcriptase polymerase chain reaction (RT-PCR) test was negative. For Brucellosis, doxycycline and rifampicin were added to the treatment of the patient whom was given supportive therapy for CCHF. In the followup, the patient’s fever was persisting and loss of taste and smell complaint developed. In this context, COVID-19 test was repeated and resulted as positive. Upon this, hydroxychloroquine sulfate treatment was started due to the recommendation of the current Ministry of Health Scientific Committee Guide. No new infiltration was detected in the chest radiography of the patient. The patient’s fever subsided during follow-up and laboratory findings improved. The treatment of brucellosis was completed to eight weeks at the outpatient clinic. No problems were detected in the follow-up. This report was prepared because of a case with simultaneous brucellosis, CCHF and COVID-19 infections which could not be encountered in the literature review. As a result; in regions such as our country where both brucellosis and CCHF are seen as endemic, it is very important to keep these diseases in mind in the differential diagnosis of COVID-19 infection.