Karyotypic analyses of 41 specimens ofForpus xanlhopterygius(Psittaciformes: Aves) reveal a diploid number of 86 and three different karyotypes were observed. A chromosomal polymorphism is present which involves two pairs of chromosomes. It is suggested that the observed polymorphism resulted from a translocation involving pairs 1 and 5. The significance of this intrapopulation variation is discussed.