Lists all 41 families, 371 genera, and 4408 species of the insect order Psocoptera (psocids) described up to the end of the year 2000. Graphically analyses the chronological discovery of species diversity. A synoptic table presents classification down to genus level with numbers of known species per taxon for each main biogeographical region of the world. Unusually also cites almost all other known references pertaining to their geographical distribution, morphology, biology, ecology, etc. Proposes several new names, synonymies, combinations, and status designations.