Aim: To investigate the transforming growth factor beta(1) (TGF-beta(1)) and basic fibroblast growth factor (bFGF) expressions in benign prostatic hyperplasia (BPH) and the effect of beta-radiation. Methods: TGF-beta(1) and bFGF expression was studied by means of an immunohistochemical method in nine normal prostatic (NP) tissues, 15 hyperplastic prostatic tissues and 35 hyperplastic prostatic tissues treated with Sr-90/Y-90. Results: The TGF-beta(1) expression in the epithelium and stroma of normal prostatic tissues was 68.2% +/- 10.5% and 29.7% +/- 4.6%, respectively, while it was 64.8% +/- 9.3% and 28.6% +/- 4.1%, respectively, in hyperplastic prostatic tissues. Compared with the controls, TGF-beta(1) expression in the epithelia and stroma of BPH treated with Sr-90/Y-90 increased significantly (P < 0.01). The bFGF expression in epithelia and stroma of normal prostatic tissues was 17.4% +/- 3.7% and 42.5% +/- 6.8%, respectively, and was 46.3% +/- 8.2% and 73.2% +/- 12.1%, respectivley, in hyperplastic prostatic tissues. Compared with the controls, expressions of bFGF in the epithelia and stroma of BPH treated with a Sr-90/Y-90 prostatic hyperplasia applicator decreased significantly (beta < 0.01). Conclusion: Exposure of beta-rays had noticeable effects on BPH tissues, enhancing TGF-beta(1) expression and inhibiting bFGF expression.