Objective: To investigate the effects of cyclosporine A (CsA) on the level of intercellular adhesion molecule-1 (ICAM-1) expressed by oral fibroblasts (FB). Material and Methods: Fibroblasts were obtained from normal buccal mucosa (NM-FB) and cultured in vitro. The expression of ICAM-1 incubated with or without CsA in 10% fetal calf serum for 48 hours at 37°C in 5% CO₂ and air was monitored by cell-based enzyme-linked immunosorbent assay (ELISA). Results: The normal expression of ICAM-1 in oral mucosal fibroblasts is 0.324 ± 0.030; CsA down-regulated the expression in a dose-dependent manner. Conclusion: CsA down-regulated the expression of ICAM-1 in oral mucosal FB, and may therefore be useful in the treatment of some oral mucosal disorders.