Recently, Human Immunodeficiency Virus (HIV) infection has become a chronic infection that can be effectively managed by early diagnosis, regular follow-up and antiretroviral therapy. With the newly diagnosed cases each year, a cumulatively increasing number of patients become HIV-infected. HIV infection and AIDS are often diagnosed with comorbidities such as opportunistic infections or malignancies that are caused by immunosuppression. However, in individuals with risky sexual behaviors and / or appropriate clinical findings, despite an irrelevant chief complaint or presentation without AIDS-defining infections, suspicion of HIV infection is very important for the early detection of the disease. In this article, we aimed to present a case of acute HIV infection mimicking acute sinusitis in a 35-year-old male patient.