In order to cope with all the natural phenomena and survive on different types of soil and in different climatic conditions, plants have perfected their means of propagation. Weed seeds are characterized by high diversity in all segments, both physical and chemical. Knowledge of the morphological characteristics of seeds and fruits of weed plants (mass, size, shape, colour, luster, odor, appearance of surface structures) is of great importance in the planning of weed control measures. The subject of this study were the seeds of the species Chenopodium album, C. hybridum, Anagallis arvensis, Veronica hederifolia and Amaranthus retroflexus, which were isolated during the weed seed bank assessment in the soil. After the physical extraction from the soil samples, the seeds were separated from the admixture, determined and then photographed with a stereomicroscope. The dimensions (length, width, seed thickness and length of the navel) were measured and any changes in the seed coat produced as a result of physical damage were monitored. The aim of this research was to expand the database, which should contribute to a more efficient determination of weed seeds. It was found that the seeds of the species studied in this paper were often broken and damaged, although in most cases with similar morphological features, as indicated by the literature data. The seeds of the species C. album were an exception, with dimensions significantly different from the data available in the literature. This occurrence can be explained by the diversity of seed anatomy in the Chenopodiaceae family and also by the fact that during their stay in the soil, permanent changes in the seed surface structures are possible.