The objective of this study was to describe the clinical and laboratory characteristics, precipitating factors, treatment, and outcome of macrophage activation syndrome (MAS) complicating systemic lupus erythematosus (SLE). A multicenter case-control study was performed across six tertiary hospitals from 1997 to 2014. A total of 32 patients with SLE-associated MAS were enrolled. Sixty-four age- and sex-matched SLE patients diagnosed in the same period without MAS episodes were selected as controls. The most frequent clinical feature was fever, followed by splenomegaly. Hyperferritinemia, hypoalbuminemia, and hyper-lactate dehydrogenase (LDH)-nemia were among the most common laboratory abnormalities. Compared with pre-MAS visit, patients at the onset of MAS had greater frequencies of renal involvement, liver dysfunction, and cytopenia. Receiver operating characteristic (ROC) analysis identified optimal cutoff values of ferritin (> 662.5 ng/mL) and LDH (> 359 U/mL) to predict the occurrence of MAS in SLE. SLE flare and infection were the common triggers of MAS in SLE. Abortion and parturition were recorded as well. The overall mortality rate was 12.5%. All patients received corticosteroids. Cyclosporine A, cyclophosphamide, and etoposide were the three most commonly used immunosuppressants. Rituximab was given to one patient. Intravenous immunoglobulin (IVIG) was added for 46.9% patients. MAS is a potentially fatal complication of SLE. Its occurrence is most frequently associated with active SLE disease or infection. The presentation of unexplained fever, cytopenia, or liver dysfunction, with high levels of ferritin and LDH, in patients with SLE should raise the suspicion of MAS. Corticosteroids with immunosuppressants and IVIG may be an appropriate treatment.