The chromosome formulae of 721 species and subspecies are reported, bringing the number of cytologically known rodent species and subspecies to 1 341, the inventory of Matthey (Mammalia 40: 453-466, 1976) taken into account. In 67.40% of the taxa listed chromosomal analysis has been performed according to the classical mode whereas in 32.60% banding methods have been used. The great increase in data on rodent chromosomes observed in the last ten years is attributed to three factors: the advent of differential staining, the utility of the karyotype in the taxonomic definition of new species and subspecies, and the existence of chromosome polymorphism. The results presented show that the contribution of banding methods to cytotaxonomic analysis is considerable. Henceforth the problem of interspecific phyletic relations will be stated in terms of genomic organization, DNA diversity, chromatin nature and repartition of different genome fractions, the relative value of the numerical criteria (2n and FN) having consequently diminished.