The potentially beneficial effect of 8-methoxypsoralen and ultraviolet A (PUVA) irradiation for treatment of drug-resistant cutaneous manifestations of graft-versus-host disease led us to investigate the effect of this therapy in a larger series of patients with GvHD. To date, 11 patients with histologically demonstrated cutaneous GvHD (acute GvHD grade III-IV in 4 patients, extensive lichenoid chronic GvHD in 6 patients, sclerodermatous chronic GvHD in 1 patient) have received PUVA treatment for 2-24 weeks. All patients have been on CsA for GvH prophylaxis; 5 with mismatched grafts had additionally received methotrexate or monoclonal antibody campath-1 after bone marrow transplantation. Seven patients were on CsA and prednisolone; 2 patients on CsA, prednisolone, and azathioprine; 1 patient on azathioprine and prednisolone; and 1 patient had no immunosuppressive treatment for the duration of PUVA treatment. The 8-methoxypsoralen (0.6 mg/kg bw) was given as photosensitizer before each ultraviolet A irradiation (0.3-8.5 joules/cm2). The only observed adverse reaction was mild nausea. In all patients improvement of cutaneous lesions could be observed with complete response in 5 patients and partial response in 6 patients. Immunosuppressive drugs could be withdrawn in 2 patients and reduced in 8 patients after initiation of PUVA treatment. These findings suggest that PUVA therapy may be a useful adjunct to conventional therapy for cutaneous GvHD.