Systemic lupus erythematosus (SLE) is characterized by a wide variety of manifestations and a difficult disease control in some patients. We present the case of a 51-year-old woman who presented with a flare of SLE including arthritis and pleuropericarditis that responded to neither leflunomide, methotrexate, nor high doses of prednisone. After initiating treatment with belimumab, the patient experienced a quick and notorious improvement. She remains stable to this day while continuing belimumab therapy.