Hodgkin's disease (HD) is characterized by the presence of Hodgkin and Reed-Sternberg (H-RS) cells against a hyperplastic background of reactive cells such as lymphocytes, histiocytes, plasma cells, eosinophils, neutrophils and stromal cells. In addition, the HD nodular sclerosis (NS) subtype shows characteristic fibrous bundles, while the other subtypes do not. The fibrosis is considered to correlate with multiple cytokines and cytokine networks. Basic fibroblast growth factor (bFGF), one of the potent stimulators of fibroblasts, has also been linked to the fibroproliferative process. To investigate the relationship of fibrosis and bFGF, we thus performed both immunostaining, in situ hybridization (ISH) and reverse transcriptase-polymerase chain reaction (RT-PCR) on 25 cases of HD, which included 12 cases with NS subtype, 10 cases with mixed cellularity (MC), and 3 cases with lymphocyte predominance (LP). In NS, the expression of bFGF was stronger than that in LP and MC. In addition, the H-RS cells in NS frequently expressed bFGF. The stromal cells and histiocytes in the background expressed bFGF in NS. However, in MC and LP the number of bFGF-expressed H-RS cells was small, and the bFGF expression of background cells was rarely detected. However, the amount of bFGF varied in each case with HD NS. The above results support the possibilities that H-RS cells and background cells are a cellular source of bFGF and that the bFGF expression of those cells is also one of the influencing factors in the development of fibrosis in the HD NS subtype.