Cyclosporin A-induced gingival hyperplasia is frequently found in the patients who have been received an immunosuppressant for the organ transplantation. However, its exact mechanism is still unknown. The expression of FGF-5 and FGF-7 were studied in cyclosporine A-induced gingival hyperplasia (CGH) and inflammatory gingival hyperplasia (IGH). Immunohistochemistry and in situ hybridization were used for localization of protein and mRNA. The expression of FGF-5 and FGF-7 was different from CGH and IGH. FGF-5 and FGF-7 was strongly expressed in fibroblast in CGH (P<0.005 and P<0.05, respectively). FGF-5 mRNA was localized in the middle portion of connective tissue. FGF-7 mRNA was also identified in fibroblasts and mast cells. In conclusion, FGF-5 and FGF-7 were produced excessively by fibroblasts in CGH. Considering their known functions, their expression in CGH is important for production of collagen and proliferation of fibroblasts.