OBJECTIVE To analyze the clinical features of patients with hemophagocytic syndrome (HPS) in autoimmune diseases (AID). METHODS We collected the data of 11 patients with AID complicated with HPS in Peking Union Medical College Hospital from 2004 to 2009. The underlying diseases, clinical features, laboratory findings and treatment outcomes were retrospectively analyzed. RESULTS Of the 11 patients, 3 were male, 8 were female. Mean age was (30.7 ± 18.3) years. The underlying diseases included Still disease (n = 4), systemic lupus erythematosus(n = 3), and rheumatoid arthritis, primary Sjögren's syndrome, Wegener granulomatosis and Crohn disease in each one case. HPS was associated with the onset of AID (n = 4), active infection alone (n = 1) and both factors (n = 6). HPS was clinically characterized by high fever (100%), hepatosplenomegaly (72.7%), lymphadenopathy (63.3%) and central nervous system involvement (36.3%). 4 patients presented with disseminated intravascular coagulation (DIC) (36.3%). Laboratory data mainly manifested with cytopenia (100%), liver dysfunction (100%), hypofibrinogenemia (62.5%), hypertriglyceridemia (81.8%), serum ferritin > 500 µg/L (100%), low NK-cell activity (80%) and hemophagocytosis in bone marrow (100%). Based on treating underlying infections and use of corticosteroids and immunosuppressive agents in combination with intravenous immunoglobulins (IVIG) therapy, 5 patients recovered, 6 patients died. The mortality rate was 54.5%. DIC were associated with mortality (r = 0.69, P = 0.019). CONCLUSIONS The episode of HPS always occurs simultaneously with multiple system involvement that was often difficult to distinguish from active AID. The present of DIC on HPS related with poor prognosis and high mortality. Corticosteroids and immunodepressant and IVIG may improve the prognosis of HPS, while anti-infection therapy is very important and necessary for the patients accompany with active infection.