OBJECTIVE: To examine the effect of recipient body mass index (BMI) on IVF outcomes in fresh donor oocyte cycles. DESIGN: Retrospective cohort study. SETTING: Not applicable. PATIENT(S): A total of 22,317 donor oocyte cycles from the 2008-2010 Society for Assisted Reproductive Technology Clinic Outcome Reporting System registry were stratified into cohorts based on World Health Organization BMI guidelines. Cycles reporting normal recipient BMI (18.5-24.9) were used as the reference group. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Implantation rate, clinical pregnancy rate (PR), pregnancy loss rate, live birth rate. RESULT(S): Success rates and adjusted odds ratios with 95% confidence intervals for all pregnancy outcomes were most favorable in cohorts of recipients with low and normal BMI, but progressively worsened as BMI increased. CONCLUSION(S): Success rates in recipient cycles are highest in those with low and normal BMI. Furthermore, there is a progressive and statistically significant worsening of outcomes in groups with higher BMI with respect to clinical pregnancy and live birth rate.