Seven oocyte donors with a levonorgestrel-releasing intrauterine device (LNG-IUD) in situ (group A) underwent ovarian stimulation with human menopausal gonadotrophin (HMG) after goserelin down-regulation, in eight treatment cycles. The donors in a control group (group B, n = 16) were comparable in age, body mass index and parity characteristics. There were no statistically significant differences in response to ovarian hyperstimulation between the two groups. The number of oocytes recovered was 12.4 +/- 5.1 (SD) following stimulation with 27.9 +/- 9.3 ampoules of HMG over 11.2 +/- 1.3 days in group A. Following stimulation with 26.2 +/- 6.3 ampoules of HMG over 11.0 +/- 1.0 days, the number of oocytes collected was 13.9 +/- 10.4 in group B. The fertilization rate (2PN/cell) of cells in group A was 63% (62/99) and in group B, 53% (117/220, not significant). The cleavage rate of cells in group A (60%, 59/99) was significantly higher than in group B (47%, 104/220) (P <0.05). On average, two embryos were transferred per cycle. In group A, the pregnancy rate per transfer was 40% (4/10) and in group B, 29% (6/21; not significant). In conclusion, LNG-IUD can be used as a contraceptive method during ovarian stimulation of volunteer oocyte donors.