Hemophagocytic lymphohistiocytosis (HLH) is an aggressive and potentially life-threatening condition characterized by uncontrolled hyper inflammation caused by various inherited or acquired immune deficiencies. We report a case of a 42-year-old man, newly diagnosed with HIV on the basis of a low CD4 T lymphocyte count (17/mm³) and HIV viral load >100,000 copies/mL by polymerase chain reaction tests who was undergoing an anti-retroviral regimen (emitricitabine, tenofovir disoproxil fumarate, ritonavir, and darunavir) and opportunistic infection prophylaxis (clarithromycin and atovaquone). He was concomitantly diagnosed with hemophagocytic syndrome, also known as HLH. He developed increasingly severe pancytopenia while on treatment with anti-retroviral drugs.