The common names of plants often cause difficulties for translators or those engaged in international studies. Although used because they are easier for non-scientists to remember than Latin or Linnean names, one species may have several common names or one common name may be used for several species. The problem is greater for weed scientists because the confusion over common names can lead to misunderstandings over control measures or the importance of weed species. The proposal to list the common names of weeds in the European languages was made in 1972 by the Joint Panel of the Evaluation of Herbicides of the European Plant Protection Organisation, and the work continued by the Working Group on Education and Training of the European Weed Research Society. The result of their labours appears in two volumes. The first is Elsevier's Dictionary of Weeds of Western Europe which was published in 1982, since when it has been a valuable source of information on the common names and importance of weed species in the countries of Western Europe. Its companion volume is this new Dictionary of Weeds of Eastern Europe. Although several books exist which give common names of plants, there are none which have the range of languages covered in these two volumes or provide information on the importance of weed species. The new dictionary will undoubtedly prove to be as welcome and as useful as its predecessor to translators, weed/crop protection scientists, botanists, ecologists, and others.