A 33-year-old woman developed progressive ovarian cancer resistant to classical chemotherapy agents. We performed a bone marrow allograft after a myeloablative regimen. During hematological recovery, she developed acute graft-versus-host disease (GVHD). From this time her tumor diminished progressively. One year post transplant she has limited chronic liver GVHD and is still free of disease. The complete remission of advanced ovarian cancer was probably related to the GVHD which might therefore provide a new treatment option for this disease.