the synergistic effects of insulin-like growth factor ii (igf-ii) and follicle stimulating hormone (fsh) and the effect of igf-ii alone on progesterone and estradiol production by bovine granulosa cells (gc) cultured in vitro were determined. granulosa cells obtained from ovaries of slaughtered cows were cultured for four days in carbon (iv) oxide incubator at 37oc, 5% co2 in atmospheric air and 100% relative humidity, using tissue culture medium 199 (tcm 199) as culture medium. the medium was changed on the second day and testosterone added to serve as substrate for estradiol production. igf-ii alone, or igf-ii (10 ng/ ml)+ fsh was added to culture medium at 0, 0.1, 1.0, 10, 50, and 100 (ng/ml) levels of inclusion. concentrations of progesterone and estradiol produced were measured by radioimmunoassay. data collected was statistically analysed using analysis of variance method. the results obtained showed that igf-ii alone and igf-ii + fsh had significant effects (p<0.05) on progesterone and estradiol produced by cultured gc. from the result obtained, it can be concluded that igf-ii + fsh gave better synergistic effects on bovine granulosa progesterone and estradiol production.