Spruce mires are rare and endangered plant communities of central and western Europe. In the Czech Republic, they were intensively destroyed and drained during the 1970s. To start the regeneration of spruce mires, palisade dams sealed with peat were used to block draining ditches in the Giant Mountains. Four years after construction of the dams, there were significant differences in vegetation above and below the dams. Vegetation above the dams successfully developed towards plant communities characteristic to spruce mire forests. Below the dams, the colonization by forest floor species continued. These differences indicate that palisade dams effectively retain water and help the regeneration of spruce mire forests. Our results support construction of palisade dams in such habitats.