The expression of endothelial leukocyte adhesion molecule-1 (ELAM-1) and intercellular adhesion molecule-1 (ICAM-1) in psoriatic lesions was immunohistochemically examined before and after various single and combination therapies. The increased staining intensity of both adhesion molecules on the proliferated papillary venules in pretreated lesion was markedly reduced after cyclosporin-A monotherapy and etretinate therapy combined with oral eicosapentaenoic acid (EPA), psoralen plus ultraviolet-A radiation (PUVA) or ultraviolet-B radiation (UVB). Less pronounced alterations were observed with etretinate, EPA, PUVA, UVB, and topical corticosteroid alone. The epidermal expression of ICAM-1, on the other hand, faded out completely following any of the treatment measures. The findings suggest that cyclosporin-A monotherapy and the etretinate combination therapies have greater inhibitory effects on the endothelial expression of the adhesion molecules than the other monotherapies. Loss of the epidermal expression of ICAM-1 may be nonspecific to the treatment.