Gaucher's disease is characterized by increased incidence of several autoantibodies, but autoimmune phenomena are rare in Gaucher patients. We report the first occurrence of Gaucher's disease and antiphospholipid syndrome in the same patient. A 27-year-old woman with hepatosplenomegaly and thrombocytopenia who was diagnosed as having Gaucher's disease with the genotype 1226G/1226G developed Coombs'-positive hemolytic anemia, recurrent abortions, and a high titer of IgG and IgM anticardiolipin antibodies constituting the diagnosis of antiphospholipid syndrome. A successful pregnancy outcome was achieved by combined therapy with aspirin, low-molecular-weight heparin, prednisone, and enzyme replacement therapy with imiglucerase. The possible pathogenicity of antiphospholipid antibodies found in the sera of many asymptomatic Gaucher patients should be further clarified.