There are literature data on the occurrence of 26 orchid species and 2 hybrids in economic poplar plantations from 13 European countries. The occurrence of 4 additional species in poplar plantations in 3 countries is proved by sources on the World Wide Web. The most widespread orchids in the poplar plantations are the rhizomatous, partial myco-heterotroph Cephalanthera and Epipactis species. Their importance is enhanced by the fact that most of the known populations of some species with a relatively narrow distribution range (Epipactis bugacensis, E. campeadorii, E. fibri, E. tallosii, E. zaupolensis) are known in poplar plantations. Cultivated poplar monocultures are likely to provide habitat for further orchids in other countries too. Most of the published papers are limited to floristic data from a single or a few plantations. Longer-term observations are only available from Poland, thanks to the work of W. Adamowski, and these suggest that populations may persist for decades and even increase dynamically. The size of orchid populations in some cases can reach thousands or even hundreds of thousands of individuals. Orchids can appear earliest in (4-)7-8 years old plantations. Very little is known about how the cultivation, structure, soil conditions and the poplar cultivars influence the presence of orchids. Mycorrhizal interactions of poplars and orchids may play a key role in this process, but the available knowledge is very limited. Furthermore, little is known about how the economic use of plantations can be reconciled with the long-term maintenance of orchid populations.