OBJECTIVE To evaluate the effects of sperm bound autoantibodies on the outcome of IVF-ET. METHODS Couples with positive antisperm autoantibodies as determined by the immunobead test were retrospectively classified into two groups: group A, consisting of 15 couples with positive antisperm antibodies in the female sera; and group B, consisting of 16 couples with sperm antibodies bound to motile spermatozoa from the male partner. Both groups were subclassified according to pregnancy outcome, i.e., pregnant and nonpregnant cycles. METHODS Thirty-one couples with positive antisperm autoantibodies were compared with 312 couples with tubal infertility undergoing IVF-ET. RESULTS No significant correlation could be shown between the mean percent binding of any specific immunoglobulin (Ig) class (G, A, and M) nor localization of sperm binding with regard to fertilization and embryonic development among pregnant and nonpregnant cycles within groups A and B. The mean fertilization rate was 59% in the control group, compared with 62% in group A and 52% in group B. Overall, the pregnancy rate (PR) in IVF-ET cycles with positive sperm autoantibodies did not demonstrate a decreasing trend compared with controls. The PR per cycle, per oocyte retrieval, and per ET was higher in group A (47%, 50%, and 53%, respectively) compared with group B (32%, 33%, and 37%) and to controls (27%, 31%, and 34%). The implantation rate was lowest in the control group (10%) compared with the study groups (group A, 20% and group B, 14%). CONCLUSIONS In vitro fertilization-embryo transfer is not significantly affected by the presence of sperm autoantibodies in female sera used to supplement the culture media or antibodies bound to inseminated sperm.