ObjectiveTo study the etiology, pathogenesis, clinical manifestations, diagnosis, treatment and prognosis of hemophagocytic syndrome (HPS). MethodsBetween February 2011 and October 2013, the causes, clinical manifestations, treatment and prognosis of 12 cases of HPS were retrospectively analyzed, and related literatures were reviewed. ResultsThere were 4 males and 8 females aged from 23 to 79 years old. Clinical features included fever (100.0%), lung infection (83.3%), enlarged lymph nodes (50.0%), bleeding (25.0%), splenomegaly (16.7%), and hepatomegaly (8.3%). Laboratory test results showed hemophagocytosis in bone marrow (100.0%), elevated ferritin (91.7%), thrombocytopenia (100.0%), decreased count in white blood cells (83.3%), decreased fibrinogen (66.7%), and hypertriglyceridemia (58.3%). Ten cases were related with infection, and 2 were related with diffused large B cell lymphoma. Nine patients died, 2 were cured, and one discharged himself from the hospital. ConclusionHPS is an uncommon disease, in which infection-associated HPS is the most common. The clinical presentation is complex, usually associated with multi-organ dysfunction, aggressive course, and high mortality rate.