The whole body of the available information on chromosome sets in parasitic wasps of the family Ichneumonidae is reviewed. New data are given on karyotypes of the following 16 species: Scambus nigricans (n = 16), Oxyrrhexis carbonator (2n = 16), Aperileptus microspilus (2n = 32), Stenomacrus sp. (2n = 28), Netelia latungula (2n = 12), Stethoncus sulcator (2n = 16), Lissonota catenator (2n = 22), L. coracina (2n = 22), Lissonota sp. (Fig. 2c), Venturia canescens (2n = 22), Rhorus extirpatorius (n = 11), Phygadeuon sp. 1 (2n = 32), Phygadeuon sp. 2. (2n = 32), Mesostenus gracilis (2n = 20), Eriplatys ardeicollis (2n = 22), and Pseudoamblyteles homocerus (2n = 18). The diploid chromosome number in Ichneumonidae varies from 12 to 42; however, the majority of species possess 2n = 22. This number is considered modal for many subfamilies, but in Microleptinae, Orthocentrinae, and most of Pimplinae, forming a single monophyletic group, the number is 2n = 28~34. Thus, both values of this index may be original for all the Ichneumonidae, although some indirect data favor the last assumption. The chromosome number usually remains stable on the generic level; however, species with aberrant n value are, as a rule, found in large genera. Sibling species are frequently revealed in such taxa.