Import of grain, seeds of other cultivated plants and agriculture production are among the main vectors for anthropogenic migrations of both native and alien plant species. A part of seeds which present as contaminants in grain or seeds of other cultivated plants enter anthropogenic or disturbed habitats at certain stages of grain transportation and treatment or with seeds intended for sowing. Diversity of wild plant seeds ocurring in imported grain and other seeds of cultivated plants was analysed in 58 shipments of grain imported in Lithuania and 2 shipments intended for export from Lithuania. Collected seeds were sown and plants grown to a stage, when their identification was possible. In total, 47 plant species belonging to 18 families were identified in the analysed samples. Majority of the identified species – 32 species – are common in Lithuania as native species or archaeophytes. Seeds of two species found as contaminents of imported grain or other seeds are frequently cultivated plants. Less than one third of species – 13 species – are alien to Lithuania. Seeds of alien plant species were recorded in shipments of grain from Belarus, Italy, Poland, Moldova, the Ukraine, and Hungary. The largest number of alien species was present in shipments from the Ukraine – 9 species. Shipments of mize grain were contaminated by seeds of 20 plant species.