Soybean (Glycine max (L.) Merr.) is one of the main legume crops in the world and in Ukraine. At the same time, its productivity is largely limited by damage by phytopathogenic fungi, among which representatives of the genus Diaporthe occupy an important place. In particular, the fungus Diaporthe caulivora (Athow & Caldwell) Santos et al. (Diaporthe phaseolorum var. caulivora Athow & Caldwell) is the causative agent of soybean stem canker, which causes necrosis of the stems with the appearance of dark brown spots on them, yellowing and wilting of the leaves. This leads to a decrease in plant yield and seed quality. Despite a significant number of studies conducted abroad, the issue of morphological identification of this pathogen in Ukrainian conditions remains relevant.