The assessment of plant species’ introduction efficiencies for wet meadows was the aim of our study. The studies were carried out as part of a project focusing on flooded meadow restoration in the Middle Vistula Valley. Twenty-six plant species of flooded meadow were in the seedling material used for renovation. The seedbed preparation covered the cutting of vegetation, ploughing, and rototilling, removing the topsoil. The diaspores after seeding were rolled and, on half of the plots, mulched with straw. The number of species, their occurrence frequency, and population abundance as well as the soil coverage by plants in the first year and the third year after diaspora seeding were determined. The seedbed preparation has restricted the occurrence and growth of Solidago sp., and increased soil coverage by meadow species. The share of introduced species in the sward ranged from 5% to 27% of coverage. The removal of the sod was significantly more efficient than other methods of seedbed preparation for plant species introduction to the renovated meadows, especially the species characteristic of the Cnidion dubii meadows. Mulching with straw generally has not improved the renovation results. Generally, Sanguisorba officinalis, Achillea millefolium, and Hypericum perforatum were the species of most frequent occurrence.