New records of the great raft spider Dolomedes plantarius in Brandenburg (Araneae: Pisauridae). The great raft spider, Dolomedes plantarius (Clerck, 1757), is a rare and endangered species in Germany and other European countries. Current data on its distribution and ecology are briefly reviewed. Five new (or overlooked) localities for this spider from the Spreewald-region of Brandenburg in eastern Germany are provided, together with an updated distribution map. One record, based on the authors' own collections, is described and figured in detail, with the egg-carrying female discovered in reeds at the edge of a fairly large body of open water. Both direct and indirect protective measures for the habitats of this species in the Spreewald-region are recommended.