Hungary represents the only country in the World where continuous earthworm research has been carried out from the end of the 19th century till now. This 120 years of faunistic and taxonomic research have required a summary for a long time, but publishing a comprehensive book depends on at least three conditions; the scientific background, willingness to write a book and the financial support. However, these three conditions are rarely given simultaneously. This is the reason why a book on Hungarian earthworms is still missing, whilst all the surrounding countries have published their own faunistic work (ČERNOSVITOV 1935, GRAFF 1953, MRŠIĆ 1991, PEREL 1979, 1997, PLISKO 1973, POP 1949). Today, it seems that all the conditions are fulfilled. The material is given, the huge collection of the second author, result of 50 years of activity, contains some 35.000 specimens from almost 1000 different localities across the country. The beginning of the new millennium (and the 75th birthday of the second author) mentally forced us to summarize our research done on the Hungarian earthworms. And last, the financial support from different organizations made it possible to publish our results. We are indebted to many colleagues who helped us with valuable comments while preparing the manuscript. In particular Sándor Mahunka and István Andrássy who took the tedious task to read the manuscript thoroughly and besides their useful remarks corrected a lot of typing mistakes as well. We wish to thank Lajos Zombori not only for linguistically polishing the text, but for his several useful editorial suggestions. We are most grateful to Zsuzsanna Ádám and Szilvia Gesztesi for the technical assistance in preparing and maintaining the earthworm database and handling the collection. The handdrawings have been prepared by Maria Csuzdi. The preparation of the computer-based earthworm database and the recent collecting activity were supported by a grant of the Ministry of Environment and Water, Hungary (KAC 0439352001), and by the Hungarian Scientific Research Found (OTKA T042745). The publication was made possible with the financial support from the joint project of the Hungarian Academy of Sciences and the Ministry of Environment and Water.