Total 240 flushings of superovulated donor cows were examined after double sedimentation. Altogether 2,810 ova and embryos, i.e. average of 11.7 per donor, including 9.0 (76.97%) transferable embryos, were obtained after the first sedimentation. The sedimentation was carried out separately for the respective uterine horns. The second sedimentation, which was carried out in the flushing from both uterine horns simultaneously, yielded ova and embryos in 82.9% (199/240) of the cases. Total 679 ova and embryos were found, i.e. 3.41 per donor, including 2.61 (76.58%) transferable embryos per donor. The increase of the yield of total ova and embryos, and transferable embryos, was 2.82 and 2.16 (24:16 and 24.04%) respectively after the second sedimentation. Altogether 3.489 total ova and embryos were obtained from 240 donors. The average embryo yield was 14.53 per donor with 76.89% (11.17) transferable embryos. The embryo yield/corpora lutea ratio was at the number of corpora lutea 12.04 on the average 120.68%. It is concluded that the second sedimentation of the flushing provides for the release of a part of the embryos for the mucous and cell aggregations, which density is usually lower. The effect of the second sedimentation is considerable, because as much as 24% of the total number of transferable embryos can be saved. The total efficiency of superovulation may be considerably decreased if no attention is paid to the above mentioned facts.