Human menopausal gonadotropins (HMG) and clomiphene citrate (CC), either alone or in combination, are frequently used for in vitro fertilization (IVF) in an attempt to maximize the number of oocytes recovered and the number of embryos transferred. However, direct comparison of the relative efficacy of these protocols in the same institution has been limited. To evaluate this question, the authors examined the outcome of 304 consecutive women attempting IVF. One hundred eighty-one women received HMG, 42 received CC, and 81 received combination HMG/CC. The percentages of women undergoing laparoscopy were not different among the groups (69%, 71%, and 74%, respectively), nor were the rates of oocyte recovery (94%, 100%, and 100%). However, the percentage of women achieving oocyte fertilization (77%, 83%, and 93%) and embryo transfer (73%, 83%, and 90%) were significantly greater among those who had received HMG/CC stimulation. A comparison of HMG/CC with HMG and CC cycles revealed a statistically significant increase in the total number of developing follicles (4.5 +/- 0.3, 3.3 +/- 0.2, and 3.1 +/- 0.3, respectively; P = 0.0137), total oocytes recovered (4.1 +/- 0.3, 3.2 +/- 0.2, and 2.5 +/- 0.2; P = 0.0011), and embryos transferred (2.2 +/- 0.2, 1.4 +/- 0.2, and 1.4 +/- 0.2; P = 0.0013). However, there was no significant difference in the occurrence of ongoing pregnancies. Thus, in terms of the per-patient number of follicles, oocytes, and embryo transfers, combined HMG/CC stimulation appears to be superior to either HMG or CC alone. However, to date the combined regimen has not improved pregnancy rates.