Abortions in horse husbandry result in significant economic losses due to fetal loss, frequent complications and prolonged treatment of mares. Non-infectious abortions are usually rare, although they can affect a larger number of individuals in the herd. Based on the Order on Measures to Protect Animal Health from Infectious and Parasitic Diseases that was valid during our research period, in case of equine abortion, sampling was mandatory in order to rule out equine viral arteritis, rhinopneumonitis, leptospirosis, contagious equine metritis and salmonellosis caused by Salmonella abortus equi. The aim of this research was to investigate the gross and histological lesions of the placenta of aborted foals, and to correlate the results of the pathological examination with the cause of the abortion. The placenta was submitted for autopsy in 61,29% of all abortion cases autopsied at the department of Veterinary Pathology, with macroscopic changes present in 73.68% and microscopic changes in 28,95% of cases. The observed pathological changes on the placentas, both macroscopic and microscopic, were nonspecific and overlapped in infectious and non-infectious causes of abortion, and most often included necrosis, hyperemia/congestion, edema and bleeding. Infectious abortions were detected more often than non-infectious abortions. In a third of the cases of infectious abortions, the pathogen was visible histologically, which, along with non-specific pathological changes that could not be linked to different pathogens and the inability of histological examination to distinguish between species of microorganisms, indicates the importance of additional diagnostic examinations in order to determine the exact pathogen. High quality anamnestic data, clinical findings and detailed pathological analysis accompanied by additional laboratory tests are imperative to determine the cause of abortion as accurately as possible.