The purpose of this study was to determine the steroid production of cultured porcine follicle cells grown in serum-free media. Theca cells (TC) and granulosa cells (GC) from large porcine follicles (greater than 8 mm) were dispersed and plated as monolayer cultures in serum-free media. Media were removed from the cultures at 3, 6, 12, 24, 48, 72, 96, and 120 h and assayed for estradiol, progesterone, testosterone and androstenedione. Both GC and TC were capable of producing progesterone, androgens and estradiol in serum-free media. GC were responsive to human chorionic gonadotropin and follicle-stimulating hormone while TC were only responsive to human chorionic gonadotropin. Growth factors, particularly insulin, appeared to enhance ovarian cells’ steroidogenesis.