Autoimmune thrombocytopenia can be a serious manifestation of systemic lupus erythematosus (SLE) which necessitates treatment with immunosuppressive agents and platelet transfusions. Interleukin-11 (IL-11) is a unique thrombopoietic growth factor which causes proliferation of megakaryocyte progenitors as well as induces megakaryocytic maturation. To our knowledge, this agent has not been used in the treatment of autoimmune thrombocytopenia, since theoretically there is a danger of IL-11 stimulating the immune system by up-regulating the lymphoid stem cells. We describe a 36-year-old splenectomized woman with known SLE who presented with pulmonary hemorrhage, acute renal failure, change in mental status, and severe thrombocytopenia (platelet count 2,000/mm3). Her pulmonary, renal, and central nervous system complications responded to intensive therapy with intravenous (IV) pulse methylprednisone and cyclophosphamide along with hemodialysis. The thrombocytopenia remained refractory to the above treatment plus daily multiple platelet transfusions and IV immunoglobulin. Treatment with recombinant human IL-11 (25 microg/kg/day subcutaneously) was initiated and continued for 5 days. Her platelet count improved to 25,000/mm3 within 48 hours, and she experienced no adverse effects.