Steroid hormone profiles during luteal phase of clomiphene citrate(CC)/human menopausal gonadotropin(hMG)/human chorionic gonadotropin(hCG)-stimulated in vitro fertilization (IVF) cycles and of follicle-stimulating hormone(FSH)/hMG/hCG-stimulated IVF cycles were compared. In seventy three cycles stimulated with CC/hMG/hCG regimen, follicles were aspirated during exploratory laparotomy and yielded 7 pregnancies, and in 83 cycles stimulated with FSH/hMG/hCG regimen, follicles were aspirated by laparoscope and made 13 pregnancies. Serum estradiol($E_2$) and progesterone($P_4$) levels were determined on days 2, 5, 7, and 9 after follicle aspiration. The FSH/hMG/hCG regimen was more effective than the CC/hMG/hCG regimen in folliculogenesis, ie, ovarian stimulation, follicular phase $E_2$ peak levels, oocyte maturation, and the number of retrieved oocytes. There was no significant difference between luteal serum $P_4/E_2$ ratio of the two regimens, suggesting that secretory endometrial build-up ability for implantation may not differ each other. Several significant correlations were observed between follicular phase seum $E_2$ peak levels and luteal phase serum $E_2$ and $P_4$ levels in the FSH/hMG/hCG-stimulated cycles but any correlation was not significant in the CC/hMG/hCG-stimulated cycles, suggesting that somewhat more follicles may eventually fall in atresia even after attaining dominant stage in the CC/hMG/hCG-stimulated cycles than the FSH/hMG/hCG-stimulated cycles.