A large number of restoration projects aims to improve the ecological quality of streams and rivers by focusingon the stream structure. However, improved habitat heterogeneity often does not lead to natural recolonizationby sensitive freshwater macroinvertebrate communities, particularly when the recolonization potential is lowand source populations are absent. In preliminary studies we tested whether natural substrate exposures could beused to sample and transport benthic macroinvertebrates. In this pilot study we used these previously testednatural substrate exposures to sample freshwater invertebrates in a donor stream in order to actively (re-)colonizea recipient stream. In the course of three reintroduction campaigns, we were able to accumulate over350,000 benthic invertebrates, including 25 indicator taxa of the orders Ephemeroptera, Plecoptera andTrichoptera and 30 taxa scoring positive in the German Fauna Index. In total, 45 taxa, which did not occur in therecipient stream before, were reintroduced. They were transported gently within natural substrate exposures andreleased on a stream bottom area of 500m2 in the recipient stream. We intended to study if an increase ofbenthos fauna in a recipient stream is possible, and if this increase will eventually improve the ecological status.So far, the natural substrate exposure-method demonstrated to be an adequate tool to accumulate and transportbenthic macroinvertebrates and, in general, has the potential to increase the biodiversity of streams when usedas assisted migration measure.