Background: Our study compares the efficacy of the combined contraceptive vaginal ring to oral contraceptive pills (OCPs) for hypothalamic-pituitary-ovarian (HPO) axis suppression in egg donor in vitro fertilization (IVF) cycles. Methods: Our retrospective cohort study includes patients from the Center for Assisted Reproduction (CARE) in Bedford, Texas undergoing IVF cycles as egg donors from January 2003 through December 2009. Twenty-five and thirty-nine women were treated with OCPs and the combined contraceptive vaginal ring, respectively. Statistical analyses were performed using the SigmaStat Software package (Systat, Chicago, IL). Data were analyzed by t or Mann-whitney test and Chi-square of Fisher exact test. Statistical significance was set at p < 0.05. Results: Prior to gonadotropin initiation, endometrial thickness and serum estradiol were 5.6±2.6 mm and 33.6±19.9 pg/ml in the OCP group and 6.0±2.4 mm and 36.6±24.3 pg/ml in the combined contraceptive vaginal ring group, respectively (p=0.49 and p=0.33). Average serum FSH and LH were 1.7±1.9 and 1.7±2.5 mIU/ml in the OCP group and 1.7±1.6 and 1.2±1.4 mIU/ml in the combined contraceptive vaginal ring group, respectively (p=0.45 and p=0.95). No significant differences were found for gonadotropin requirement, peak estradiol, maximal endometrial thickness, number of oocytes retrieved, number of normally fertilized embryos, number of cryopreserved embryos, or live birth rates. Conclusion: The combined contraceptive vaginal ring is effective for HPO axis suppression in egg donor IVF cycles and associated with cycle characteristics similar to those observed with OCP treatment. The combined contraceptive vaginal ring may provide an important advantage over OCPs due to improved patient compliance.