Cell culture and biochemical techniques have been employed to examine the effects of steroids, bromocriptine, and epidermal growth factor (EGF) on the growth and proliferative potential of meningiomas. In cell culture, the growth of meningiomas was not altered by progestogens, antiprogestogens, or 17beta-estradiol. The progestogen, norethisterone, had no effect on the uptake by meningiomas cell cultures of 3H-thymidine. Furthermore, cytosolic deoxyribonucleic acid (DNA) polymerase activity of meningiomas did not correlate with the progesterone receptor status of the same tumors. In contrast, the androgen antagonists, cyproterone acetate and 11-alpha-hydroxyprogesterone, and the dopamine agonist, bromocriptine, all inhibited the in vitro growth of meningioma cells. The growth of meningioma cell cultures was stimulated by EGF, and there was a positive correlation between the EGF content and DNA polymerase activity in meningioma cytosols. These results demonstrate that female sex steroids do not influence growth of meningiomas in vitro, whereas antiandrogens and bromocriptine have an antiproliferative effect. Consequently, bromocriptine and antiandrogens may have a role in the medical treatment of meningiomas. In addition, these results suggest that EGF may be involved in the genesis and/or progression of meningiomas.