The immunosuppressive effects of the sedative drug thalidomide have been utilised in a variety of immune disorders. In the present study, 6 patients were treated who developed graft-versus-host disease (GvHD) following allogeneic bone marrow transplantation (BMT) with thalidomide and in a dose range of 200-600 mg daily. Two of 3 patients with chronic GvHD showed clear improvement, whereas none of the 3 patients with acute GvHD derived unequivocal benefit. Although based on a small number of patients, these data suggest that thalidomide may find a useful place in the therapy of GvHD, perhaps specifically in the chronic form of this disorder.