A previously unreported type of male pseudohermaphrodite sheep is described. The animal had XY sex chromosomes in all tissues studied and was chromatin negative. It had female external genitalia and undescended testicular gonads, with an histology distinct from that of previously reported sheep intersexes. Its origin could not be explained on the same basis as the more commonly reported female (XX) intersexes seen in man and other domestic animals. Comparison, however, of this sheep with the ovine cryptorchid suggests that the germ-cell aplasia seen in the latter is genetically determined and due to a possible gene locus or loci deletion of the Y chromosome.