A series of 273 breast cancer biopsies were analysed immunohistochemically for the expression of transforming growth factor beta-1 (TGF-beta 1) and beta-2 (TGF-beta 2) as related to standard prognostic factors and patient survival. TGF-beta 1 expression was found in 160/273 (59%) and TGF-2 in 110/273 (40%) of tumour specimens. Both isoforms were expressed in 89/273 (33%) of cases. TGF-beta 1 alone was expressed in 71/273 (26%) of cases and TGF-beta 2 alone was expressed in 19/273 (7%) of cases. The expression of TGF-beta 1 and TGF-beta 2 were both uniformly related to some other favourable prognostic factors. The expression of TGF-beta 2 without the expression of TGF-1 was significantly related to favourable disease outcome. The result of this study is in agreement with the previous studies of TGF-beta mRNA and also in vitro studies, but the result differs from some previous immunohistological studies. This study also suggests that the expression of TGF beta may have independent prognostic value over the expression of TGF-beta 1.