Embryo transfer is a reproductive technology commonly used around the world to reproduce animals with high genetic merit. However, the application of embryo transfer (ET) technology in combination to artificial insemination (AI) can improve the reproductive performance of high producing dairy herds. The main reason for that potential improvement is the higher fertility reported after embryo transfer in cows experiencing heat stress and those diagnosed as repeat-breeders. Heat stress has a deleterious effect on fertility in dairy herds around the world, especially in tropical areas in which summers are hot and humid. Studies have shown that embryo transfer is an effective tool to increase fertility during heat stress because it bypasses the damage to the oocyte and early embryo caused by hyperthermia. Therefore, a useful management tool to maintain high pregnancy rates throughout the year would be to produce embryos during the cooler months and use them for ET during the periods of heat stress. Repeat breeder cows are usually defined as cows that do not become pregnant over a period of time (usually after 3 or 4 unsuccessful breedings). The reasons for poor fertility in these cows are still controversial. However, the transfer of embryos to repeat breeder recipients resulted in increased repeat breeder pregnancy rates compared with AI, supporting the notion that the fertility problem in some repeat-breeders may be associated with oocyte quality and/or failure of early embryo development. In summary, although the embryo transfer technology has been used primarily to reproduce animals with high genetic merit, this technology can be used to resolve reproductive problems such as the reduced fertility found during heat stress and in repeat breeder cows.