A double reciprocal translocation has been found in a morphologically normal but infertile bull (Bos taurus), using trypsin-Giemsa banding. The karyotype of the bull can be written as: 60,XY,t(2q-;20q+),t(8q-;27q+). Cytophotometric studies supported the findings in the karyograms and identified the breakpoints in the chromosomes involved. The possible effect of this translocation heterozygosity on male fertility is discussed.