The C- and G-banded karyotypes of five species of waxbill finches belonging to the Estrildidae were examined. Extensive chromosomal variation including inversions and fissions was found to differentiate the species, showing the waxbills to be the most chromosomally diverse group of estrildid finches. None of the variation, however, matched that recorded in related species of Pytilia (Christidis, 1983). By comparing the G-banded karyotypes of species belonging to all three estrildid lineages it was possible to reconstruct the presumed ancestral karyotype for the Estrildidae as a whole. This was found to approximate the karyotype of the Australian peophilid species, Poephila guttata most closely. From it chromosomal relationships within the three estrildid lineages, Poephilae, Lonchurae, Estrildae, can be determined.