Current purification processes allow the production of highly purified human menopausal gonadotrophin (HP-HMG), with human chorionic gonadotrophin (HCG) constituting most of its LH-like activity. This retrospective study aimed to compare the effectiveness of HP-HMG to the widely used traditional human menopausal gonadotrophin (HMG) preparation. A total of 174 women undergoing intracytoplasmic sperm injection cycles were allocated to either HMG or HP-HMG for ovarian stimulation. The number of mature oocytes was significantly higher in the HP-HMG group (14.72 +/- 7.81) than in the HMG group (12.15 +/- 11.07) (P < 0.05). However, the number of good quality embryos was not significantly different between both groups (HMG: 1.65 +/- 1.54; HP-HMG: 1.78 +/- 1.41). Similarly, there was no statistically significant difference in number of embryos transferred per woman (HMG: 3.95 +/- 1.87; HP-HMG: 4.27 +/- 1.60). The pregnancy rate per woman was 38.39% versus 51.79% in the HMG- and HP-HMG-treated groups respectively. These findings suggest that HP-HMG produces more mature oocytes than ordinary HMG, but similar pregnancy rates.