Due to the prominent dieback of the narrow-leaved ash (Fraxinus angustifolia Vahl) and the absence or low seed yield over the last few years, the aim of this study was to establish the presence of potentially pathogenic fungi and pests in seeds as well as to determine the presence of the pathogenic fungus Hymenoscyphus fraxineus in seeds, since this fungus is the main reason for ash dieback. The analysed seeds were collected from five locations (forest offices Novoselec, Lipovljani, Gunja, Županja, Vukovar). These seeds were analysed by the classical fungal isolation methods onto the artificial nutrient media, after which the obtained mycelia from 42% of the seeds were identified by the molecular methods. The analysis showed 15 different fungal taxons. The most common was the genus Alternaria and the species Spahaerulina berberidis, which has not been found on the ash seed so far. The presence of pests in the seed was quantified by visual inspection of the seeds, and two types of insects were found: the ash weevil from the genus Lignyodes and the parasitic wasp on the weevil. The percentage of the seed attacked by pests was 5.8%. Although a large number of identified fungi have previously been described as seed and fruit pathogens, and some as opportunistic ash (Fraxinus spp.) parasites, all of the inspected seeds were of good vitality, with the exception of the seeds attacked by the ash weevil. These results may indicate a possible reduction of seed vitality over longer storage periods and in conditions of increased moisture. Pathogenic fungus Hymenoscyphus fraxineus was not found in the seeds of narrow-leaved ash.