In seminatural grasslands, the success of reintroduction of locally extinct rare plant species may depend on the ambient management regime. We aimed to study to what extent the success of the restoration of a rare species (Gladiolus imbricatus) depends on management conditions. A management experiment with traditional cutting by scythe and hay removal, mowing (machine cutting and hay removal), mulching (machine cutting without hay removal), spring burning, and unmanaged control, combined with reintroduction of seeds of Gladiolus, was conducted in an Estonian flooded meadow in which the species had become extinct. Seeds were reintroduced in 2003 in all management treatments and populations monitored until 2006. Mulching, mowing, and traditional management resulted in the greatest establishment, whereas the subsequent mortality was not influenced greatly by management regime. The population started to increase in mulching treatment in the third season due to vegetative growth. The results indicate that the establishment of G. imbricatus is primarily seed limited under current conditions, whereas favorable management significantly enhances establishment in a river floodplain meadow. Successful restoration depends on seed addition and proper grassland management—mowing to a height of approximately 15 cm and mulching.