Growth factors from neural tissues have been described as potent mitogens for a wide variety of mesoderm- and ectoderm-derived cells in vitro. We used porcine brain extract for in vitro testing of proliferation properties on primary ovarian cells, uterine cells, and cardiomyocytes in culture as well as for BHK-21 [C-13] cell line. The addition of this extract accelerates proliferation in all examined cultures. It also lowers serum requirement and shortens the cultivation period for BHK-21 [C-13] cells. Fibroblast growth factors from brain of different species, but not porcine, are already characterized and their proliferative effect proved. Therefore, we purified, determined, and confirmed the presence of basic fibroblast growth factor in porcine brain extract by Western blot analysis and showed its biological activity on BHK-21 [C-13] cells.