Familial hemophagocytic lymphohistiocytosis is a rare and inherited disease that affects both males and females equally and is most often fatal if not treated. Diagnosis is challenging because it mimics severe sepsis by demonstrating hepatomegaly, splenomegaly, persistent fever, central nervous system involvement, and cytopenias. The etiologies of hemophagocytic lymphohistiocytosis have been well established through the identification of 3 causative genetic mutations. Therapies for hemophagocytic lymphohistiocytosis focus on restoring health by diminishing the disease sequelae with a goal of hematopoietic stem cell transplant, the only known curative therapy for hemophagocytic lymphohistiocytosis. Current research is being conducted to identify other causative genetic mutations and newer, more effective treatment modalities.