(Background)The aim of this study was to estimate the prevalence of disease processes in Yili horses. To our knowledge, this type of post-mortem survey has not been conducted in the Yili of Xinjiang since the 1970s. The Yili horse, known as “China’s first horse,” is an important breeding horse and has thus played an essential role in the development of animal husbandry in China. Zhaosu county is one of the primary areas for the breeding of Yili horses. Currently, there are 97,400 Yili horses in Zhaosu, accounting for 80.4% of the breed’s total population. (Objectives)To gain a better picture of the health of individual horses, (Methods) we collected information on disease processes related to all findings and on analysis considered to be related to the cause of death from 210 consecutive post-mortem examinations of Yili horses performed at the department of Animal Epidemic Disease, Forestry University of Beijing, between February 2014 and February 2024. ( Results)Pathology results revealed that the most frequently diseased systems were the alimentary, cardiovascular, respiratory, endocrine, and locomotor systems. The most common specific entities were those related to endoparasitism and its associated vascular lesions, as well as pneumonia and fractures. (Conclusions)These results may reflect poor healthcare awareness among local herders and that injuries increased because this breed was used for racing more in recent years.