OBJECTIVE To investigate the effects of cyclosporin A (CSA) on the level of intercellular adhesion molecule-1 (ICAM-1) expressed by oral fibroblasts (FB). METHODS The fibroblasts were obtained from normal buccal mucosa (NM-FB) and cultured in vitro. Then the levels of ICAM-1 expressed by fibroblasts incubated with or without CSA in the presence of 10% fetal calf serum for 48 hours at 37 degrees C in 5% CO(2) and air were monitored by using cell-based ELISA for ICAM-1. RESULTS We demonstrated that NM-FB had ICAM-1 expression (A = 0.324 +/- 0.030), and after 48 hours incubated with CSA the ICAM-1 levels expressed by oral buccal mucosa fibroblasts were dose-dependently decreased. CONCLUSIONS CSA reduces the levels of ICAM-1 expressed by oral mucosal FB, and may be useful in the treatment of some oral mucosal disorders.