Artificial insemination (AI) is the most widespread, commonly used and simplest method of assisted reproductive technology (ART) with numerous advantages for breeders. It also has the great importance in Croatian horse breeding, which, following the trends in Europe, is constantly moving forward. AI has significant effect on genetic progress in horse breeding and selection programmes and enables the efficient exploitation and control of the fertility of mares and stallions, the prevention of the dissemination of sexually transmitted infectious diseases in horses, the international trade of chilled and frozen semen and the use of the best quality stallions for breeding and more effective genetic testing through his offspring. Special importance is shown in the preservation of endangered autochthonous and protected horse breeds through long-term storage of deep-frozen stallion semen. In the Republic of Croatia, AI could be used for import of high-quality genetic material in breeding and selection programmes, which would create a base for breeding high-quality sports horses, and also for genetic rescue and cryopreservated semen banking of endangered autuchthonous horse breeds. However, despite the extreme importance of the AI use in horse breeding, the Annual Report of the Croatian Agency for Agriculture and Food shows that the number of foals in relation to the number of mares is far below the European average, from which it can be concluded that the fertility of horses of all breeds in Croatia is unsatisfactory. Due to the fact that this important method of ART is still not recognized as a component of strengthening breeding on the one hand, and due to the constant need to train doctors of veterinary medicine on the other hand, we are still far behind other countries of the European Union in terms of breeding warm-blooded horse breeds.